Add support for decoding to 565 to libjpeg_turbo

It was submitted upstream at libjpeg_turbo as r1295 plus
sundry fixes and SIMD optimizations (r1385, r1386, r1398,
and r1402).  Now cherry pick the change into
third_party/libjpeg-turbo.

At this time, this new capability is intended for Android
devices, not Chrome, and should have no affect on JPEG
decode behavior or perf of Chrome.

BUG=516761
R=noel@chromium.org

Review URL: https://codereview.chromium.org/1270213002 .
18 files changed