Review request for CR 7147456

[Greg Brown]

Based on feedback on macosx-port-dev, this change flattens the key structure used in the plist for JavaAppLauncher. It also renames the generated "JavaVM" to "Java" to clarify the folder's intent (the folder does not contain a Java VM but rather resources related to execution of the Java part of the launcher app):

http://mail.openjdk.java.net/pipermail/macosx-port-dev/2012-February/003239.html

Webrev: 
http://cr.openjdk.java.net/~gkbrown/7147456/webrev.00/