Added the api warning for newly added classes.

Patch by: amitmanjhi
Review by: rjrjr (tbr)

Review at http://gwt-code-reviews.appspot.com/619804


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@8310 8db76d5a-ed1c-0410-87a9-c151d255dfc7
5 files changed