Code cleanup and conversation refactoring first phase.
Second part of conversation refactoring is finished. One to one chat is now using refactored conversation logic.
Merge branch 'feature-20141015-contacts-refactoring' into feature-20141211-hybrid-dev

Conflicts:
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/ActiveSessionTableViewCell.m
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/ActiveSessionsViewController.m
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/AddParticipantsViewController.m
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/MainViewController.h
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/SessionManager.h
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/SessionManager.m
	Samples/OpenPeerSampleApp/OpenPeerSampleApp/SessionViewController_iPhone.m
	openpeer-ios-sdk.xcodeproj/project.pbxproj
	openpeer-ios-sdk/model/HOPConversationRecord+External.h
	openpeer-ios-sdk/model/HOPConversationRecord+External.mm
	openpeer-ios-sdk/source/HOPModelManager.mm