Rollback of r10726. It still causes brackage

*** Original change description ***

Change default of UiBinder.useLazyWidgetBuilders to true, in
preparation for deleting the old code.

Review at http://gwt-code-reviews.appspot.com/1577805


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10727 8db76d5a-ed1c-0410-87a9-c151d255dfc7