move time indicator to function & add date as title & label for diff days messages

If message is following message from another day it should have date indicator.  [Might want to do message separators like skype].
Also this PR adds title to time. [Might consider switching for even more detailed representation - for example: 'Friday, February 15, 12:34:52']

![image](https://f.cloud.github.com/assets/1506905/2179272/a726a37a-969d-11e3-8010-1457096d6779.png)