Comment 8 for bug 1008721

Finally committed the patch from Bug #840860.

RE: Waveform changes I ended up leaving out some of the AnalyserQueue changes -- particularly the part with the semaphore because it causes priority inversion with the main thread. Basically the analyser cannot make any progress until the main thread reacts to it. It seemed like added the 60ms buffering of progress updates was enough to majorly cut down on the signal noise and WOverview redraws.

RE: Eliminating frees of Waveform objects, I removed that as well. The main reason was that it doesn't really save many memory allocations since the initially created Waveform objects are pretty small (no data is stored in them so its just a handful of pointers). Inflating the protobuf when reading the waveform from file takes tons of memory so the savings are really small compared to that.