VBInputSourceManager listening to own user and immediately sending notifications after mic processed.

re:issue #15 

- added property listenToUser on VBInputSourceManager which sets the current user to listen to (can be self or nil for listening to own mic)

- added isSubscribedToOwnMicInput to figure out whether it should listen to network pub sub notifications or just results of it’s own mic for immediate NSNotification


The end result is that if VBInputSourceManager is listening to the current user, it notifies immediately upon processing the mic results, otherwise it subscribes to pubsub for any updates on a user's network channel.