Simplifying refactor of FocusImpl now that all modern browsers support focusable divs.  Also fixes some issues associated with accessKeys.

Patch by: jlabanca
Review by: jgw
Issue: 1313,1471,2072,2590,3355,3363,4273



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7390 8db76d5a-ed1c-0410-87a9-c151d255dfc7
13 files changed