- 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