[IMP] im_chat, im_livechat : make the option adding easier by creating a dropdown menu from the header of a conversation. It will contain 'quit conversation', 'transfer discussion', 'screenshare', ...
[FIX] im : add cr.commit() at the right place. This avoid latency between notify and listen
[FIX] im_chat : change the way catching click_header to avoid StopPropagation for each button in the conversation header
[IMP] im_chat : add quit conversation option
[IMP] im_livechat : add functional field to extract stats and adapt views