we can now receive normal and chat messages with subject and handle them ok. we can also reply to received normal message with RE: previous message and all the good stuff! hoooray!

last_message_time is now saved in gajim.py so we begin to count time when we receive the message and not when we print it (fix #162)

if the resource is empty do not add an extra / [we do not known the resource if we are lower than mod in a muc and we ask version info