Removing RichTextArea API additions introduced in r5630 and r5631 because some people may be extending these interfaces, which makes these breaking changes.

Patch by: jlabanca
Review by: kprobst



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@5723 8db76d5a-ed1c-0410-87a9-c151d255dfc7