Groupchat into Roster bugs and problems

[jim++]

• Middle click on groupchat in roster doesn't open it.
• It's now like notify_on_all_muc_messages is always on, even when it's not and even when group chats are not minimized (critical)
• We should have a way to see for minimized rooms in roster if there are only some messages, or if we were highlighted. And not be notified in systray if it's not an highlight (if notify_on_all_muc_messages is False) I guess. But I don't really see how to do this. Maybe add notify_on_all_minimized_muc_messages option. But it's not perfect, because one may want to see there is new messages but without maximising groupchat nor see a notification in systray.

[jim++]

After discussions with asterix for the third point :

For a simple message, show a message icon in roster only. Do not add an event to event system.

For a highlighted message, show a message icon in roster, add * before the name in roster (like in message window tabs). Add an event to event system (so we see it in systray).

[roidelapluie]

(In [8155]) (Fix #3174) Groupchats in roster: Open groupchats with middleclick, fix notifications in systray and print number of unread marked messages in roster.