Bump to latest Android and AppCompat
Drop v14+ styles

To quote Chris Banes (https://chris.banes.me/2014/10/17/appcompat-v21/):

For apps which already have existing appcompat setups, this means that you should remove your v14+ themes which re-set the same values in the android namespace.
Use latest android dependencies
Port to material design

This still crashes on lolipop, let's see how we can replace the image downloading code