Comment 0 for bug 1431616

This has spawned from an idea to ameliorate bug #1431168.

On some systems generating waveform/bpm analysis data for the first time can be intensive enough to disturb playback in a set, and in my case my system has even locked up. As a safety feature, and because it is weird that you currently can't, it seems smart to have a way to turn off generation for un-analyzed tracks.