Issue #984 Improve module listing

Changed |= to ?= for optional property set

jetty-server/src/main/config/modules/session-store-cache.mod

@@ -15,7 +15,7 @@ etc/sessions/session-data-cache/session-caching-store.xml
 
 
 [ini]
-session-data-cache|=xmemcached
+session-data-cache?=xmemcached
 
 [ini-template]
 

jetty-server/src/main/config/modules/session-store-jdbc.mod

@@ -15,7 +15,7 @@ sessions/jdbc/${db-connection-type}
 etc/sessions/jdbc/session-store.xml
 
 [ini]
-db-connection-type|=datasource
+db-connection-type?=datasource
 
 [ini-template]
 ##

jetty-start/src/main/java/org/eclipse/jetty/start/StartArgs.java

@@ -1064,7 +1064,7 @@ public class StartArgs
                     source=propertySource.get(key)+","+source;
                 }
             }
-            if (key.endsWith("|"))
+            if (key.endsWith("?"))
             {
                 key = key.substring(0,key.length()-1);
                 if (getProperties().containsKey(key))

jetty-start/src/main/resources/org/eclipse/jetty/start/usage.txt

@@ -157,7 +157,7 @@ Properties:
     name+=,value
       Add to an existing property as a comma separated list.
 
-    name|=value
+    name?=value
       Set a property only if it is not already set.
 
     STOP.HOST=[string]

jetty-start/src/test/resources/usecases/basic-properties.assert.txt

@@ -14,3 +14,4 @@ PROP|other=value
 PROP|jetty.http.port=9090
 PROP|add=beginningmiddleend
 PROP|list=one,two,three
+PROP|name=value

jetty-start/src/test/resources/usecases/basic-properties.cmdline.txt

@@ -6,3 +6,5 @@ add+=end
 list+=,one
 list+=,two
 list+=,three
+name?=value
+name?=enoughAlready