Review request for fix for legacy jdk image

[Mandy Chung]

The jdk modules build change causes two regressions in the legacy jdk 
images:
1. the modules build creates a module library under <outputdir>/lib/modules
    that gets copied to the legacy jdk image
2. the launcher runs in module mode as supposed to run in legacy mode

Alan,

Can you review the fix in the launcher and the modules build makefile:
  http://cr.openjdk.java.net/~mchung/jigsaw/launcher-in-legacy-image/

Thanks
Mandy