Adding support to multiple screens.

Nowadays, MM doesn't supports multiple screens (e.g. tablets) in a great way.
We starting to add this by replacing activities to fragments.

Some references:

Supporting Multiple Screens
http://developer.android.com/guide/practices/screens_support.html

Designing for Multiple Screens
http://developer.android.com/training/multiscreen/index.html

Fragments:
http://developer.android.com/guide/components/fragments.html