PrKalmanFilter but as a Tool!
Much of KalmanFilter::operator()'s code is put into functions in header KF.h such that they can be used in the Tool. A new interface is introduced for the Tool. The KalmanFilter Algorithm still exists and shares most code with KalmanFilter Tool. Also a bug is fixed that assigned PrForward history and Long track to every v1 output track. For this, history is also introduced in LHCb::Pr::Long::Tracks to keep track of the algorithm that produced the Long track. Also v1 tracks now have additional info (chi2s) consistent with MasterFitter.
Goes with LHCb!3247 (merged) and Moore!1087 (merged)