Created ChatClientContext for session management of the ChatClient

ACE-28
Merge branch 'master' into createImplementationOfServiceAPI_ACE-27

Conflicts:
	org.ualerts.chat.web/src/main/java/org/ualerts/chat/web/sockjs/SockJsHandler.java
Added expectations for the ChatClient.setConversation method call to
each test in ConcreteConversationTest