- New startActivityForResult() API.
- Fragments now should have the correct lifecycle while hanging around
in the back stack (not being destroyed and re-created).
- Rework of state save/restore to make it simpler and better. In theory
now any fragment (including layout and others in the hierarchy) can
now be retained across config changes, though this hasn't been tested.
Change-Id: I2a7fe560e14e567f5675a2f172a23fca67b3e97f
6e8304e57e