Changes

=====Session transmissiontransition=====

Each confirmed participant (user_in_room_state == CURRENT_USER) keeps to indicators: * active_session The active_session is the only session changes which is in IN_SESSION state. A session state moves to IN_SESSION when the user receives session confirmation from all users have confirmed participants. In that case the previously active session state will be DEAD. When a new session get activated, all STALE sessions gets refreshed. That is, all sessions which were requested to be created (due to join or leave) during the creation of the newly active session, will be recreated according to the new participant list. Further more, the next_in_activation_line also points to the newly activated session.  * next_in_activation_line  When a user leaves while another user trys to join, the leave protocol will take priority and a new participant info message is sent to the joining user after all leaving users have left. When multiple users are joining, when the confirmed participant receives the first joiner auth, it will halt the protocol for other joining users. When the session is confirmed, the new participant info list will be sent to the remaining joining users. Joining user (user_in_room_state == JOINING) does not keep any indicator.