[Build] Add useful vendor version number to Windows and Mac OS X builds
Merge branch 'stable'
[Frontend-GNOME] /window command cycles through tabs with same name
Merge pull request #87 from oli-obk/feature/window_command
[lib/agsxmpp, Engine-XMPP] respond with service-not-available to unknown stanzas

required refactoring to use nice C# Events instead of c style callbacks
Merge pull request #88 from oli-obk/fix/invalid_iq
[lib/agsxmpp] service-unavailable messages can now be canceled
[Engine-XMPP] only send service-unavailable stanzas to the server and to contacts that are subscribed to the user
[Engine-XMPP] cleanup inconsistent use of IsConnected and JabberClient.Authenticated
[Engine-XMPP] don't send groupchat part command to server while not connected
Merge pull request #89 from oli-obk/fix/error_response
Merge pull request #90 from oli-obk/refactoring/IsConnected