changed stats module to use more efficient computation methods
Cleaned up stats.py, and added documentation for scipy.stats module.
Runge-Kutta code working for ball - w=0, no initial vertical velocity.
Slight format changes. Beginning of section on ball tracking.
Added omega (launch angle). same results as scipy ode package.
Got wind for baseball working. But, don't think I want to include it.

Going to remove wind in the next check in.
Added dimensions for x and z in Kalman filter __init__
Test code to perform KF on ball in vacuum.
Got air drag working well, and a KF showing the errors due to the process model.