Catch timeouts from any model or collection

#48 close
Added globalInitialize constructor for error handling of session timout
event.  This will not be overriden if a initialize is added to any
particular model for other purposes.
Refactored context_app.  Still need to add a message bus to show why
the session was ended, that's only in the console right now.
Removed messages from backbone.sef.js.