ROLLED BACK AT r4334 DUE TO BUILD BREAK.

Added tests for arg processing of the main GWT entry points.
- Some testability tweaks on the classes being tested.


git-svn-id: https://google-web-toolkit.googlecode.com/svn/releases/1.6@4327 8db76d5a-ed1c-0410-87a9-c151d255dfc7