Support Java 6 as a source language.  For 1.5 VMs, rewrite v6 class files to v5.

Review by: tobyr
Issue: 2223


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@3648 8db76d5a-ed1c-0410-87a9-c151d255dfc7
3 files changed