Added test for Unsubscribe
Updated some docs and misc clean up
Removed some echoes from the AuthenticationManager
Subscribe returns promise now. "exclude_me" = false implemented - still need to add to features though
Add example with MetaEvent function
Major rework of RPC - added Procedure class
Multiple RPC registrations for same procedure
Fix php docs for example
Implement CancelMessage
Fix php docs and coding style
Merge origin/master

Conflicts:
	src/Thruway/Call.php
	src/Thruway/Message/ErrorMessage.php
	src/Thruway/Role/Subscriber.php
Fix php docs and coding style after merge code