[Halld-offline] recent change to tracking code

[Simon Taylor]

Hello, everyone.

I have made the following change to the Kalman Filter code:  instead of 
providing 5x5 covariance matrices and 5x1 state vectors whose meaning 
depended on which parametrization was used in the fit, if the forward 
parametrization was used I have now rotate the 5x5 matrix and 5x1 state 
vector from this space into the central parametrization; in other words 
all the tracking results are now stored in DKinematicData using the 
state vector {q/pT,phi,tanl(lambda),D,z}.

Simon