Reorganize validation classes and minimize visibility in preperation for removing the Experimental tag. [JSR 303 TCK Result] 151 of 257 (58.75%) Pass with 32 Failures and 7 Errors. Review at http://gwt-code-reviews.appspot.com/1565807 Review by: rjrjr@google.com git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10702 8db76d5a-ed1c-0410-87a9-c151d255dfc7