A mechanical refactoring of the Precompile options as prep for further cleanup. Added @Override annotations to satisfy the IDE warnings with Java 1.6 enabled. Review at http://gwt-code-reviews.appspot.com/1452804 git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10230 8db76d5a-ed1c-0410-87a9-c151d255dfc7