Make nick cycle works with spaces in nicks, fix a possible bug if gc_refer_to_nick_char is not ",". Fixes #3810.

* Make usage of history_window (hopefully) more straight forward. (widget placement, focus, shown nicks, completion...)
* Kill two bugs where wrong nicknames were shown in chathistory and results window.
* Rename functions to make clear that their are intended for private usage only.

Continue to check message for HL words after we found one that could be only the beginning of another real word.

roster : Fix resource problem, gajim.contacts.get_contact() can return first contact instead of specified resource. Fixes #3789.

Single window mode to any other resulted in the roster being the size of the roster + any chats that were in the orignal window.  This fixes that. (#3713)

show invitation from anonymous room in roster from a groupchat rather than from a normal Contact. fixes #3448

-Check if there are pending events and send offline even if we don't ask a status message (was a indentation
mistake I think)
- Really make unread and recent working according to 'notify_on_all_muc_messages' value
- be faster, hopefully

Use only one function when user wants to quit. Bad dup code !
Maybe see #3643.