[roidelapluie, elghinn, msieurhappy, xbright and me] chat to muc convertion. see #2095 and #1408. TODO: DND

Set unusable menuitems insensitive instead of hiding them.
Enhance transport roster menu. Fixes #3383

show search results in correct columns if result is not in the same order as <reported> element. fixes #3379

in accounts window, save jid, resource and custom port when we change row in accounts treeview. Fixes #2744