Patch refactors SessionHandler and BrowserChannelClient to enable OOPHM clients
other than HtmlUnit. Removes need for UnsupportedOperationException and adds
generics to SessionHandler.

Patch by: t.broyer@gmail.com
Review by: amitmanjhi, jat


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7603 8db76d5a-ed1c-0410-87a9-c151d255dfc7