Tabbed case detail

FB129673

Technical spec: https://confluence.dimagi.com/display/ccinternal/Tabbed+Case+Detail

Not-so-technical spec: https://docs.google.com/a/dimagi.com/document/d/1MiGqDJA59ZN9ycEWuq5ObVc9lhpVe0TgwCAfInhDzF8
I did not. Looking at it now...I could make childDetail and entity class variables that get created in onAttach so they don't get re-created unless the entire fragment is destroyed.