Better error reporting. Also, move the proxy and request interfaces to shared, where they belong — the servlet validates against them. Review at http://gwt-code-reviews.appspot.com/1444801 Review by: jlabanca@google.com git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10168 8db76d5a-ed1c-0410-87a9-c151d255dfc7