Rework build to enable future jigsaw aware JDK9 build

This is a baby step towards JDK-8161704.

The change consists of several related changes:
   1) clean up generated-source paths to allow for a future module-source-path that is cleaner (or at least shorter).
   2) remove dependencies on BUILD_SRC
       + move the JSLC sources out of buildSrc into the graphics module, though only as an intermediate build product.
   3) rework the complex graphics module build to create clearer dependancy graph that does not include buildSrc.
   4) set up graphics for a two pass java compile (first pass creates decora compiler required classes, the second generates the full module)
   5) address JDK-8091264 - Upgrade to newer version of antlr