fix arguments of on_open_chat_window functions. It is called from callbacks, so first argument is widget.

 * Show all groups in merged accounts view that have online contacts. Fixes #3890
 * Allow metacontacts over several accounts. Fixes #3889
 * Fix on_drop_in_group when two accounts in merged view have the same contact
 * Fix potential traceback when receiving a message

It's cleaner and less error prone, so simply use it everywhere.

http://python.org/dev/peps/pep-0008/ " Comparisons to singletons like None should always be done with
'is' or 'is not', never the equality operators."


Apply do roster_window. See r9488.

This is only a simple port of the old non-modelfilter method. Functionality not restored yet: Custom colors are lost when refiltering the model.

Change the way last_history_time for room is saved. Save time in mem at each message logged. When closing
control, save the value in rooms_last_message_time table. Previous version could introduce duplicate logs or
messages not logged.

Moved newly created auto_join_bookmarks() to good source file.
Fix :
-when using bookmark auto from join dialog : Action rebuild now done; Add GC sorted in list
-when using gc_control->bookmark : Store password if any.

Moved methods for opening new messages controls from roster.py to src/gajim.py. This is not roster related. See #3643.
Sorted src/gajim.py functions, using steve-e style :p

Contacts are now online hidden when they connect/reconnect and not completely removed/readded. Should come with a great speed improvement for people with big rosters.
There are still a few known problems but non that should dalay this patch any longer. Related bugs will be tracked with 'modelfilter' keyword.

See #1201