Fix a bug when toggling SSL that caused the app to stop working after
two toggles of the switch:

* Work around the fact that PTPusher still tries to reconnect if you
explicitly call 'disconnect' by causing the old client to become 
deallocated instead (where it will safely disconnect without any
further callbacks)

* We need to setup a new disconnection handler too as that also has
a strong reference to the client.

* We need to explicitly connect the new client as we no longer do this
 in the _setupPusher method.
Update the UI to reflect that we are connecting using the appropriate
PTPusher delegate method, not during setup.