Engine-XMPP: regression from fc69d82cead caused NRE when sending messages to bare Jids

this was noticed in gtalk, as messages there are always sent to bare Jids.
calling /whois on a contact to which such a message had been sent caused the NullRefException.
this will be properly fixed in refactor/XmppResourceModel
Frontend-GNOME: fixed imperfect topic height
Merge branch 'stable'
Frontend-GNOME: fixed typo in variable name which broke the build
Merge branch 'stable'
Merge pull request #155 from oli-obk/fix/regression_send_message
L10N: remove auto generated smuxi-engine-twitter.pot
L10N: fixed typo in variable name
Transifex: added new translation domains smuxi-engine-(jabbr|xmpp) and smuxi-frontend-gnome-(twitter|xmpp)
Engine-XMPP: joining a muc, where another resource of the same account is already in, didn't work

i was trying to be smart and reuse the XmppPersonModel for mucs, but it's just not that simple
Merge pull request #157 from oli-obk/fix/double_muc_join
Frontend-GNOME: fixed stuck sync progress bar

Chats there were never synced but removed never triggered a progress bar update
thus the progress bar continued to show unfinished progress till the next sync
happens and completes.
Merge branch 'stable'
Build, Frontend-GNOME: use dbus-sharp-2.0
Travis-CI: build with dbus-sharp(-glib)-1.0
Frontend-GNOME-XMPP: MessageType.Presence* didn't mark chatnodes with event color

HasEvent is only set for the contactlist and groupchats. Private chats are ignored on purpose:
In XmppPersonChatView only the most recent Presence state is shown (or for PresenceOnline nothing is shown). So it could have happened that a contact goes offline and back online, causing HasEvent to be set, but the MessageTextView of the XmppPersonChatView hasn't changed. Therefor the user would not see what has happened and wonder why his chatnode is colored in the event color.
contactlist and groupchats do not handle Presences in a special way, therefor these messages are always visible.
Merge pull request #158 from oli-obk/fix/presence_event_tab_color
Engine-Twitter: fixed build regression on .NET 2.0/3.5
Engine-Twitter: workaround compiler bug of Mono 2.6.7
Frontend-GNOME: don't show desktop notifications for active chats