2.4.5 Release

Added video and audio quality flags for conversion (see VideoAttributes.quality and AudioAttributes.quality)
Changed aac de/encoder from libvo_aacenc to default aac settings from ffmpeg
Upgraded windows and osx binaries to 4.1 from https://ffmpeg.zeranoe.com/builds/
Upgraded linux binaries to 4.1 from https://johnvansickle.com/ffmpeg/