CompileModule creates a serialized set of compilation units to represent
a GWT module as a <module>.gwt file.  This is intended to be run when building
a library to support incremental compilation of a module.

Review at http://gwt-code-reviews.appspot.com/1448808


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10304 8db76d5a-ed1c-0410-87a9-c151d255dfc7