Incorporating the crashing fix by robmaceachern from here: https://github.com/robmaceachern/GPUImage/commit/fd4e39b2079057064f9549a7911ad7ea31e0ad62#diff-d41d8cd98f00b204e9800998ecf8427e
callback for video loading to properly setup video for render
separate Picture initialization from processing so the image can be later updated
disable framebuffer reference counting if the check for it is disabled to prevent overrelease
ability to toggle video writing synchronization
colorAtLocation in the rawData class doesnt need to flip height