paplayer: use position based seeks for ffmpeg demuxer
ensure we exit the lock prior to calling PrunePackageCache() as this takes ages, and will grab graphicscontext lock, leading to deadlocks
adds fix_alert_handling.patch from 0.9.8za to fix issues with github hosted repositories
[rbp] Fix leaks in the failure handling of jpeg decode to texture

There are a couple of cases where memory could be leaked after an allocation failure
when decoding jpegs to textures.