Forward-port surface dithering from CM10.1

This allows the use of 16-bit color displays without excessive color
banding;

Change-Id: Icb469b9cb4beb686516c60bb576dbd0a73f505e0
Prefer 16bpp surface formats

Adds a property to use RGB565 surface formats for the opaque
surface default, enabled by default.

Change-Id: Iac9bbc8292a863e2ab86093df3ecf218e4ec61e1
don't use fence sync for qcom legacy display

Change-Id: I4e7df9ac5c6e2eb5e6f923c907d0ec8d391a93d8
separate mHeap-based screenshot from BOARD_EGL_NEEDS_LEGACY_FB

No need for the Exynos/Tegra legacy fb implementation on legacy
qcom. Add a separate flag for mHeap-based screenshot in case of
future extensions. Enable mHeap-based screenshot for legacy qcom
dislay.

Change-Id: I35ff015555f19a5ba2857ad3d765d02eb6b9acde
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

Change-Id: I89ab1d60b23eef55442a9fd338b2a05b3304ce61