Revision 1421944

For the compile target, set javac source and target options to 1.6.  This will allow us to use FlashBuilder 4.7 with the SDK when the compiler is built with Java 1.7 since FB supports Java 1.6 but not 1.7.  All the other compiler modules set these javac options to either 1.4 or 1.5. 

I chose 1.6 to avoid many warnings of this style:
warning: as of release 5, 'enum' is a keyword, and may not be used as an identifier

but this should be ok since we require a minimum of Java 1.6 according to our README.