This commit makes a number of improvements when importing the
Elasticsearch project into IntelliJ IDEA. Specifically:
- Contributing documentation has been updated to reflect that the
'idea' task should no long be used and Gradle project import is
instead the officially supported way of setting up the project.
- Attempts to run the 'idea' task will result in a failure with a
message directing folks to our CONTRIBUTING.md document.
- The project JDK is explicit set rather that using whatever JAVA_HOME
is.
- Gradle build operation delegation is disabled, and test execution is
configured to 'choose per test'.
- Gradle is configured to inherit the project JDK.
- Some code style conventions are automatically configured.
- File encoding is explicitly set to UTF-8.
- Parallel module compilation is enabled and deprecated feature
warnings are disabled.
- A remote debug run configuration using listen mode is created.
- JUnit runner is configured with required system properties.
- License headers are configured such that Apache 2 is the default
notice added to all source files with exception of source in /x-pack
which will use the Elastic license.