Start index and length + AOSP-style buttons + Recently used tabs

I tested it a bit, it should work fine. I made this feature available only to TextViews.

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
I modified it a bit, it should work now. I wrote a little test class: https://gist.github.com/daniele-athome/da180d811d5663bd5b6b
Commit is on its way.