Fixes RichTextArea.isEnabled/setEnabled functionality so that it actually enables/disables the text area. Patch by: manolo.carrasco Review by: jlabanca Issue: 1488 git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7528 8db76d5a-ed1c-0410-87a9-c151d255dfc7