I haven't checked whether reverting this breaks IME input, and if it doesn't what changed on wx's end. However, this is the commit that uses private symbols, and so reverting it lets us build against upstream wx. Even if this is a loss in functionality, for now it's fine.
Add a new Project class which is responsible for everything related to
opening and closing audio, video, subtitles, timecodes and keyframes.
This pulls almost everything not directly related to playing audio/video
out of the audio and video controllers, pulls more crap out of
FrameMain, and happens to make things a little simpler in the process.
