Implemented suspend / resume support
Moving towards a full comet implementation.  Next up, sessions.
Implemented sessions using a singleton actor to hold references and handle expirations.  Comet still isn't working, but it's closer now.
Streams need to be explicitly closed if they are left open in an unsuspended request.

I imagine that the servlet container takes care of this, so Lift doesn't seem to always close them.  If they remain unclosed, the page never fully loads and no scripts are executed.  This commit also includes some fixes for my Netty session implementation.
Fixes necessary to add session and comet support.  Comet works!
Merge pull request #5 from davewhittaker/master

Working comet.  Give it a whirl.