NIFI-558: Improvements to "Getting Started" instructions for first build.

* when we tell folks to go somewhere, give them a link
* make sure building of nifi-parent is called out
* provide guidance on when to build parent / nar-plugin
* include requirements before folks start trying to build
* make sure there are shell examples for deployment commands
* make sure shell commands work for copy-paste after this version (even if
  captured responses will have different output later).
* include a screenshot of what a correct build + deploy + launch looks like
  in browser.

Signed-off-by: Aldrin Piri <aldrinpiri@gmail.com>

README.md

@@ -24,9 +24,42 @@ Apache NiFi is an easy to use, powerful, and reliable system to process and dist
 
 ## Getting Started
 
+- Read through the [quickstart guide for development](http://nifi.incubator.apache.org/development/quickstart.html).
+  It will include information on getting a local copy of the source, give pointers on issue
+  tracking, and provide some warnings about common problems with development environments.
+- Optional: Build supporting modules. This should only be needed if the current 'nifi' module is in
+  the process of updating to a new version of either the 'nifi-parent' or 'nifi-nar-maven-plugin'
+  artifacts.
+
+    If in doubt, just skip to building the main nifi project. If the build fails, come back here and
+    figure out which optional step you are missing; each entry below will give an example of the
+    errors you'll receive if that step needs to be followed. The version numbers may change but the
+    error text should still look very familiar.
+    - Install the nifi-parent pom. Change directory to 'nifi-parent' and follow the directions found
+      there in [README.md](nifi-parent/README.md).
+
+    If you don't build the nifi-parent pom and the main nifi code relies on an unreleased version
+    you'll see an erorr like the following:
+
+        [ERROR]     Non-resolvable parent POM: Could not find artifact
+            org.apache.nifi:nifi-parent:pom:1.0.0-incubating-SNAPSHOT in example.snapshots.repo
+            (https://repository.example.com/content/repositories/snapshots) and
+            'parent.relativePath' points at no local POM @ line 18, column 13 -> [Help 2]
     - Build the nifi-nar-maven-plugin.  Change directory to 'nifi-nar-maven-plugin' and
-follow the directions found there.
+      follow the directions found there in [README.md](nifi-nar-maven-plugin/README.md).
-- Build nifi.  Change directory to 'nifi' and follow the directions found there.
+
+    If you don't build the nifi-nar-maven-plugin and the main nifi code relies on an unreleased
+    version you'll see an error like the following:
+
+        [ERROR]     Unresolveable build extension: Plugin
+            org.apache.nifi:nifi-nar-maven-plugin:1.0.1-incubating-SNAPSHOT or one of its
+            dependencies could not be resolved: Could not find artifact
+            org.apache.nifi:nifi-nar-maven-plugin:jar:1.0.1-incubating-SNAPSHOT -> [Help 2]
+- Build nifi.  Change directory to 'nifi' and follow the directions found there in
+  [README.md](nifi/README.md).
+- Run NiFi. The directions found in the [README.md](nifi/README.md) file within the 'nifi' module
+  will also include how to run an instance of NiFi. For help on how to build your first data flow,
+  see the [NiFi User Guide](http://nifi.incubator.apache.org/docs/nifi-docs/user-guide.html).
 
 ## Documentation
 

nifi-nar-maven-plugin/README.md

@@ -18,16 +18,25 @@ Apache NiFi NAR Maven Plugin helps to build NiFi Archive bundles to support the
 
 ## Table of Contents
 
+- [Requirements](#requirements)
 - [Getting Started](#getting-started)
 - [Getting Help](#getting-help)
-- [Requirements](#requirements)
 - [License](#license)
 - [Disclaimer](#disclaimer)
 
+## Requirements
+* JDK 1.7 or higher
+* Apache Maven 3.0.5 or higher
+
 ## Getting Started
 
-To Build:
+Building the nifi-nar-maven-plugin module should be rare since it will be released infrequently compared to
-- Executed 'mvn clean install'
+the main 'nifi' code tree.
+
+- Build with `mvn clean install`
+- Presuming you need to make use of changes to the nifi-nar-maven-plugin module, you should next
+  go to the [nifi](../nifi) directory and follow its instructions. 
+
 
 ## Getting Help
 If you have questions, you can reach out to our mailing list: dev@nifi.incubator.apache.org
@@ -36,9 +45,6 @@ We're also often available in IRC: #nifi on
 [irc.freenode.net](http://webchat.freenode.net/?channels=#nifi).
 
 
-## Requirements
-* JDK 1.7 or higher
-
 ## License
 
 Except as otherwise noted this software is licensed under the

nifi-parent/README.md

@@ -18,16 +18,24 @@ Apache NiFi Parent provides a nice aggregation of shared concerns for all NiFi P
 
 ## Table of Contents
 
+- [Requirements](#requirements)
 - [Getting Started](#getting-started)
 - [License](#license)
 - [Disclaimer](#disclaimer)
 
+## Requirements
+* JDK 1.7 or higher
+* Apache Maven 3.0.5 or higher
+
 ## Getting Started
 
-- Build the nifi-parent module.  Then you can go to the 'nifi-nar-maven-plugin' 
+Building the nifi-parent module should be rare since it will be released infrequently compared to
-directory and follow its instructions and finally the 'nifi' directory.  Building
+the main 'nifi' code tree.
-the nifi-parent and nifi-nar-maven-plugin should be rarely necessary as these 
+
-will be released infrequently by comparison to the 'nifi' tree.
+- Build the nifi-parent module using `mvn clean install`.
+- Presuming you need to make use of changes to the nifi-parent module, you should next
+  go to the [nifi-nar-maven-plugin](../nifi-nar-maven-plugin) directory and follow its instructions
+  and finally the [nifi](../nifi) directory. 
 
 ## Documentation
 

nifi/README.md

@@ -19,9 +19,9 @@ Apache NiFi is an easy to use, powerful, and reliable system to process and dist
 ## Table of Contents
 
 - [Features](#features)
+- [Requirements](#requirements)
 - [Getting Started](#getting-started)
 - [Getting Help](#getting-help)
-- [Requirements](#requirements)
 - [License](#license)
 - [Disclaimer](#disclaimer)
 - [Export Control] (#export-control)
@@ -47,17 +47,64 @@ Apache NiFi was made for dataflow. It supports highly configurable directed grap
   - SSL, SSH, HTTPS, encrypted content, etc...
   - Pluggable role-based authentication/authorization
 
+## Requirements
+* JDK 1.7 or higher
+* Apache Maven 3.0.5 or higher
+
 ## Getting Started
 
 To build:
-- Execute 'mvn clean install' or for parallel build execute 'mvn -T 2.0C clean install'
+- Execute `mvn clean install` or for parallel build execute `mvn -T 2.0C clean install`. On a
-- Change directory to 'nifi-assembly'. In the target directory, there should be a build of nifi.
+  modest development laptop that is a couple of years old, the latter build takes a bit under ten
-- Unpack the build wherever you like or use the already unpacked build.
+  minutes. After a large amount of output you should eventually see a success message.
 
-To start NiFi:
+        laptop:nifi fhampton$ mvn -T 2.0C clean install
-- Change directory to the location where you installed NiFi
+        [INFO] Scanning for projects...
-- '<install_location>/bin/nifi.sh start'
+        [INFO] Inspecting build with total of 115 modules...
-- Direct your browser to http://localhost:8080/nifi/
+            ...tens of thousands of lines elided...
+        [INFO] ------------------------------------------------------------------------
+        [INFO] BUILD SUCCESS
+        [INFO] ------------------------------------------------------------------------
+        [INFO] Total time: 09:24 min (Wall Clock)
+        [INFO] Finished at: 2015-04-30T00:30:36-05:00
+        [INFO] Final Memory: 173M/1359M
+        [INFO] ------------------------------------------------------------------------
+
+To deploy:
+- Change directory to 'nifi-assembly'. In the target directory, there should be a build of nifi.
+
+        laptop:nifi fhampton$ cd nifi-assembly
+        laptop:nifi-assembly fhampton$ ls -lhd target/nifi*
+        drwxr-xr-x  3 fhampton  staff   102B Apr 30 00:29 target/nifi-0.1.0-incubating-SNAPSHOT-bin
+        -rw-r--r--  1 fhampton  staff   144M Apr 30 00:30 target/nifi-0.1.0-incubating-SNAPSHOT-bin.tar.gz
+        -rw-r--r--  1 fhampton  staff   144M Apr 30 00:30 target/nifi-0.1.0-incubating-SNAPSHOT-bin.zip
+
+- For testing ongoing development you could use the already unpacked build present in the directory
+  named "nifi-*version*-bin", where *version* is the current project version. To deploy in another
+  location make use of either the tarball or zipfile and unpack them wherever you like. The
+  distribution will be within a common parent directory named for the version.
+
+        laptop:nifi-assembly fhampton$ mkdir ~/example-nifi-deploy
+        laptop:nifi-assembly fhampton$ tar xzf target/nifi-*-bin.tar.gz -C ~/example-nifi-deploy
+        laptop:nifi-assembly fhampton$ ls -lh ~/example-nifi-deploy/
+        total 0
+        drwxr-xr-x  10 fhampton  staff   340B Apr 30 01:06 nifi-0.1.0-incubating-SNAPSHOT
+
+To run NiFi:
+- Change directory to the location where you installed NiFi and run it.
+
+        laptop:~ fhampton$ cd ~/example-nifi-deploy/nifi-*
+        laptop:nifi-0.1.0-incubating-SNAPSHOT fhampton$ ./bin/nifi.sh start
+
+- Direct your browser to http://localhost:8080/nifi/ and you should see an screen like this screenshot:
+  ![image of a NiFi dataflow canvas](nifi-docs/src/main/asciidoc/images/nifi_first_launch_screenshot.png?raw=true)
+
+- For help building your first data flow see the [NiFi User Guide](http://nifi.incubator.apache.org/docs/nifi-docs/user-guide.html)
+
+- If you are testing ongoing development, you will likely want to stop your instance.
+
+        laptop:~ fhampton$ cd ~/example-nifi-deploy/nifi-*
+        laptop:nifi-0.1.0-incubating-SNAPSHOT fhampton$ ./bin/nifi.sh stop
 
 ## Getting Help
 If you have questions, you can reach out to our mailing list: dev@nifi.incubator.apache.org
@@ -65,9 +112,6 @@ If you have questions, you can reach out to our mailing list: dev@nifi.incubator
 We're also often available in IRC: #nifi on
 [irc.freenode.net](http://webchat.freenode.net/?channels=#nifi).
 
-## Requirements
-* JDK 1.7 or higher
-
 ## License
 
 Except as otherwise noted this software is licensed under the