[devel] Replaced a short but frequently-used memcpy() in png_combine_row()

with a loop.
(cherry picked from commit fa7d7934f608edcb9ca7c36f0a74256a4fd7aaa8)

Conflicts:

	ANNOUNCE
	CHANGES

Change-Id: Ia3752ca10bdb6a994680152afd7d4aee9ecb0f9e
[devel] Improved the optimization of the zlib CMF byte

(see libpng-1.2.6beta03).
(cherry picked from commit 28534bd47a511fdfe8a544ddee09eba70debdbf3)

Conflicts:

	ANNOUNCE
	CHANGES

Change-Id: I7b316b780b855d9643e2de6d410f8503a706f1b7
VeNum optimizations to libpng to improve PNG decode time

Set correct counter in neon routine for SUB filter type.
Enable Neon optimizations for all filter types and pixel depths.

(cherry picked from commit b912f64bc4bb174fc055cda58e303faaa640b8b1)

Conflicts:

	pngrutil.c
(cherry picked from commit fa02de5150971c6c0fa789a38bca32dece879d2b)

Change-Id: I444ba064fb978934e74b63f169440e9f1e4ac1bc

Conflicts:

	Android.mk

Conflicts:

	pngrutil.c
Fix build with gcc 4.8+

Change-Id: Id8021170ed9e1abaa1aff336d6b1c164704e568a
external: libpng: fix numerous compiler warnings

Clean up the code for unused variables to handle them
a bit more elegantly.

Change-Id: I8b01c27673128719dad74276599d5a286c4dd412

Conflicts:

	pngpread.c