* Buttons get disabled as needed now [we still need something to update
  this while the window is open (it might change, for example, the
  contact was added)].
* Remove the new accelerators in destroy_menu().
* Move some OTR stuff.
* Don't hide OTR from the user if not available, but set unsensitive.

Work done by Kjell Braden <fnord@pentabarf.de>.
Some fixes done by me.

 * remove unused code
 * use self.model directly when obvious
 * cleanup some FIXME comments

And fix that stupid bug that glade will introuce again and again
(it's just to stupid to keep the image None and replaces it with
gtk-missing-image, so you always see a stupid image as avatar when
there's none)

* Moved some code so we can get rid of a few ifs.

What still needs to be done for the GUI redesign to be complete:
Don't show entries in the actions menu that have buttons.

Sync groups of metacontacts to fix a potential bug. Contact iters of brothers might not be found, though they are in roster.

command? This is far more userfriendly. If you have any objections,
feel free to revert and I'll think of something else that's not as
annoying as /say.

In configure room, works even if we receive an affiliation list with more than one affiliation inside.
More logical, more secure and example 90 in xep-0045 says it can happen. Deal also with affiliation 'none' (don't show it)

few pixels above close.