onTouchEvent calls super.
Revert "onTouchEvent calls super."

This reverts commit f1f3f0f9f46f50513a60d0ee9f4861c1053e047e.
Improved angle math.

FIRST, you must subtract the start angle from theta (the raw atan of
delta-x and delta-y).  Only after you have done this should you convert
to a positive angle(by subtracting from 360 if negative).
Cleaned up code.

Removed log messages, unnecessary comments, "frame marks" in onDraw.