Adds detachBuffer and attachBuffer calls to both the producer and
consumer sides of BufferQueue. Buffers may be detached while dequeued
by the producer or acquired by the consumer, and when attached, enter
the dequeued and acquired states, respectively.
Bug: 13173343
Change-Id: Ic152692b0a94d99e0135b9bfa62747dab2a54220
Now that BufferQueue has been split into core + producer + consumer,
rewrite BufferQueue to be a thin layer over a producer and consumer
interface. Eventually, this layer will be deprecated in favor of
only using either the producer or consumer interface, as applicable.
Change-Id: I340ae5f5b633b244fb594615ff52ba50b9e2f7e4