SurfaceFlinger: Change to support framebuffer flip for 2D blitters

- Surfaceflinger does not flip framebuffers when there are
  no layers marked for HWC_FRAMEBUFFER
- This change checks for the HWC_BLIT flag and will request a flip
  to a new FB_TARGET buffer even if there are no FRAMEBUFFER layers

Change-Id: I1cb44389a05c9ec049d7f0d39c288feccb11a91c
sensorservice: Set the rate for pre-1.1 HALs _after_ activation

We want to be sure these are applied in the same sequence they
used to be...

Change-Id: Ied2ba08ed3c4bed3a80bac6ab5471fcea9ba2c09
surfaceflinger: Consolidate display orientation compensation hooks

Dedupe rotation calculation code and make rotation a statically
available property in the DisplayDevice
Change-Id: Ic517ab0d2c05026cd6fa46d664aab7926be17b62

Conflicts:
	services/surfaceflinger/DisplayDevice.cpp