[WIP] some message styling

playing with the messages view...

- after first changes ![2014-11-14 11 21 58](https://cloud.githubusercontent.com/assets/658431/5044400/a502bf06-6bf0-11e4-8e17-a4faf4a6ae40.png)

- [ ] invert messages stream as a work around (Xamarin.Forms ListView doesn't allow scroll to bottom)