* WIP: XEP-0198 Stream Resumption

This patch implements a first cut of XEP-0198
Stream Resumption for TCP and WebSockets.

This appears to work on (very) basic testing, but
the code is very likely to run into problems with
existing code assuming that LocalSession.getConnection()
never returns null, and similar issues.

This is likely to generate unexpected (and
possibly unhandled) NPEs.

The basic premise to the design is that
StanzaHandlers (or similar) and Connections
from the new session are re-pointed to the old
session. The old session lives on in limbo with its
conn field set to null during detachment.

I strongly suspect that bits are missing from this,
but so far...

* Fix CR/LF

* WIP

* WIP

* Close detached 198 sessions after timeout

Also:
* Quick audit of LocalSession.getConnection
* Add in guard code for LocalSession.getConnection

* CRLF

* CRLF