Updates MobileWebApp to use GWT Maven Plugin 2.3.0-1
- It now honors scope "provided"
- Its is not necessary to clean up gwt-dev.jar nor gwt-user.jar

Review at http://gwt-code-reviews.appspot.com/1525806


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10549 8db76d5a-ed1c-0410-87a9-c151d255dfc7