Comment 9 for bug 325377

This patch is against trunk.

New features:
1. Improved inertia
In my last patch, if track is paused, waveform stopped with a jerk
Now if play button is not pressed waveform doesn't stop with a jerk

2. Some fancy stuff
- A hand appears while mouse scratching
- Mouse motion (in X direction) is restricted to waveform display only

What other things need to be addressed before mouse scratching really makes it to trunk?