Android MediaCodec

Adds Android 4.1+ MediaCodec implementation for DVDPlayer.
This is POC, sw-rendering only and needs surface rendering added.
Works for 1080p/720p under Odroid/U2, 720p under Nexus7/Ouya (Tegra3).

Requires PR https://github.com/xbmc/xbmc/pull/3081 (which is included) plus the PR 3081 fixes (also included)