NB 7.2 HR integration review request: #207981:Problems with setting java platforms

Description:
http://netbeans.org/bugzilla/show_bug.cgi?id=207981

In the project system queries it's impossible to distinguish Java Platforms created for the same SDK, the query implementor gets the URL of rt.jar.
If one platform is configured with sources and javadoc and the second has no sources and javadoc attached the navigation
and javadoc may not work depending on the order of platforms. While it's not possible to distinguish the Java Platforms it's
possible to ignore the unconfigured platforms while configured one exists for the same SDK.

Impact assessment: Affects mostly JFX projects which clones existing JavaPlatform

Risk assessment: The platform SourceForBinaryQueryImplementation is a sensitive core service which affect complete java
infrastructure. QA should intensively test the change both correctness and performance testing is needed.

The fix has been reviewed by Jan Lahoda

Changeset:
http://hg.netbeans.org/main-silver/rev/f5d8d77a4577

Thanks for the review,
  Tomas