RFR: Post-modules and module images build in new buildsystem

[Erik Joelsson]

I have converted the post modularization step from the old build system 
to the new build system in jigsaw.

http://cr.openjdk.java.net/~erikj/jigsaw/webrev.post-modules.01/

The images target will now produce the same module and base images as 
the old build. The legacy images can still be built using the new target 
"legacy-images". All the post modularization steps happen in the target 
"post-modules". I have verified the build manually on linux, windows, 
solaris and mac and also run it successfully through jprt (with a 
limited set of tests). I've compared the contents of the built modules 
with the old build (see below for differences).

Known issues:

* Fastdebug fails, both in old and new build, when running the newly 
built rmic at the end of the jdk target.
* No fast incremental support in the post-modules or images targets. 
Trying to fix that instead of working on a real modular build seems like 
a waste of time.
* The following differences with the old build have been observed:
   * Debug info files (*.diz) from hotspot, but not from the jdk, are 
included in the modules in the old build. I chose to treat all *.diz 
files the same and chose to exclude them for now.
   * The swingbeans (dt.jar) are generated during images creation in the 
old build, but in the new build those classes are compiled with the 
rest, making them available to the modularization. This makes them 
present in the jdk.desktop module in the new build.
   * Similarly META-INF/services/com.sun.tools.xjc.Plugin is generated 
earlier in the new build and is now present in jdk.tools.jaxws.
   * sun/text/resources/th/BreakIteratorRules_th.class is showing up in 
sun.localedata.

/Erik