Phase 2 of readying samples for distro.
- Added a top-level ant file for the distro/samples to build or produce eclipse projects in bulk.
- gwt-dev is now an explicit dependency so that Showcase can compile

Review by: amitmanjhi (TBR)


git-svn-id: https://google-web-toolkit.googlecode.com/svn/releases/1.6@4573 8db76d5a-ed1c-0410-87a9-c151d255dfc7