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

[Erik Joelsson]

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. I'm also removing some dead code in 
RMICompilation.gmk.

This should very slightly improve incremental build performance on Windows.

Bug: https://bugs.openjdk.java.net/browse/JDK-8221703

Webrev: http://cr.openjdk.java.net/~erikj/8221703/webrev.01/

/Erik