Rmic build for java.management.api has bad incremental behavior

In Rmic-java.management.api.gmk, there is a special extra rule defined to move the generated class and java files into different directories. This construct doesn't really work well in make and on incremental builds, one of the recipes is always executed.

I'm rewriting this by implementing direct support in SetupRMICompilation for separate output directories.

This should very slightly improve incremental build performance on Windows.