Merge pull request #1716 from xsacha/master

New Option for Blackberry keyboard devices: Partial Vertical Stretch
add NPUMDIMG support
Improve remainFrame.
Add FFMPEG libraries to Android build. Update ffmpeg submodule.
Merge branch 'cv47-patch2'
Merge pull request #1718 from tpunix/master

Add PSN demos support
Merge pull request #1719 from oioitff/atrac-fix

Improve remainFrame for sceAtrac.
Build fix, sorry.
Merge pull request #1720 from oioitff/atrac-fix

Build fix, sorry.
Buildfix: Symbian, CMake-based compiles.
Update ffmpeg (added missing headers for android)
Android buildfix
Windows: Use prebuilt FFMPEG for 32-bit builds.
Mac build fix
Keep track of whether a texture has alpha.

This way we know what sorts of blending we even have to do.  Commonly,
textures don't have any real alpha.

Not yet used for anything.
Ignore texfunc RGBA when texture is full alpha.

This allows us to skip some work in the fragment shader.
Detect clears, replace with glClear(). Needs more testing, disabled for now.
Clean up some comments.
Merge pull request #1727 from unknownbrackets/perf

Keep track of whether textures have alpha values or not
Make some logging VERBOSE