Added features:
* added '+AESDecrypt:' and '+AESDecrypt:error:' methods into PubNub to allow developer decrypt objects which arrived from another PubNub client
* added '+AESEncrypt:+' and '+AESEncrypt:error:' methods into PubNub to allow developerd encrypt objects to be send to another PubNub client
* copied library into demo projects
* updated library information (debug output in console)
Merged with hotfix-t171