More jigsaw cleanup

[Mandy Chung]

I'm going to push this set of minor fixes:
- clean up modules.config and modules.group
- ClassLoader - remove the hackBootPath done for J1 demo
- fix jigsaw jtreg tests to run on Windows.

Webrev:
   http://cr.openjdk.java.net/~mchung/jigsaw/more-cleanup/

Thanks
Mandy