Prototype of reconnect code.

When ejabberd is restarted with `ejabberdctl restart` the node-xmpp
client does not enter a reconnect state. Instead the connection is
ended. This code attempts to handle reconnection in a somewhat janky
way.

A more intelligent backoff is probably required.
Remove build data from package.json.
Add sinon dependency.

Testing timers is much easier with sinon.
Add tests and fixes for reconnection logic.
Remove event listeners on reconnect.

Remove any listeners from the previous connection as they can cause
issues with messages being logged more than once.
Merge pull request #66 from markstory/fix-reconnect

Fix reconnection issues