Fixed issues:
* broken subscribe request in case if disabled presence channel was last one with which PubNub library worked at that moment
* tweaked reconnection GCD block, to make it impossible schedule few of them (they confused connection channels a bit)
* tweaked completion of presence enable/disable on channels on which it is already enabled/disabled
* copied library into demo projects
* updated library information (debug output in console)
Performed tweaks:
* now client identifier can be reset only with '+setClientIdentifier:'. If 'nil' is passed, new UUID will be generated (even if it already assigned)
* copied library into demo projects
* updated library information (debug output in console)
Merge branch 'hotfix-t165' into 3.5.1rc1
fixing merge conflicts
bumping version