use av_frame_alloc() if lavc is >= 55.28.1
avoid an implicit type conversion in a shader

renderprogs/interactionSM.pixel does not compile with the Mesa
shader compiler due to a an implicit type conversion.

This gives a console warning on a release build and fatally
asserts on an debug build:

0:135(19): error: could not implicitly convert operands to arithmetic operator

Avoid this by changing an int declaration to a float.
Fix memory corruption in timidity resampling code.

From Sam Lantinga in SDL_mixer 1.2.8:
http://lists.libsdl.org/pipermail/commits-libsdl.org/2007-July/008673.html

Fixes a crash on OpenBSD.
Merge pull request #144 from jonathangray/timidity-resample-fix

Fix memory corruption in timidity resampling code
Merge pull request #143 from jonathangray/mesa-shader-fix

make a shader work with Mesa by avoiding an implicit type conversion
Merge pull request #140 from darealshinji/patch-1

use av_frame_alloc() if lavc is >= 55.28.1
Merge remote-tracking branch 'upstream/master'