libagl: Allow use of copybit to accelerate 2D rendering

This appears to fix the 2D performance issues on msm7225 and msm7227,
no more stutter in animations or transitions
Enable with TARGET_LIBAGL_USE_GRALLOC_COPYBITS := true

Change-Id: If1e06dc2b7836e370053d1c664fe5192619e3015
surfaceflingerconsumer: Select texture target based on pixel format

Adreno is not optimized for GL_TEXTURE_EXTERNAL_OES, making GPU
utilization (and power), high with GL_TEXTURE_EXTERNAL_OES for
RGB formats.
Change texture target from GL_EXTERNAL_TEXTURE_OES to dynamically
select between GL_EXTERNAL_TEXTURE_OES, and GL_TEXTURE_2D based
on the pixel format.
This change is done to reduce the composition time for 8x55
*Ported from ics
*ifdef for BOARD_ADRENO_DECIDE_TEXTURE_TARGET

*Ported to Android 4.3

Change-Id: I2ec2ceeee6b201d4d2c8e8227ccb4789f957da23

Conflicts:
	services/surfaceflinger/Android.mk