Implemented KalmanTrackerFF for fast flows as a separate method

[Lollum89]

NOTE: This new pull request is in substitution of #295. All the modifications are made in a new tracking method, KalmanTrackerFF, to avoid interfering with the existing one, as suggested by @tinevez .

In this version I made an improvement in the tracking of fast flows using the Kalman Tracker. Essentially, I added a new field in the tracker, which is called expectedMovement. It is an array, therefore representing the X;Y;Z displacement vector. In the fast flows, initiating a track is not optimal, as the spots might move a lot in a preferential direction. In the Jaquaman linking step of the tracker, the origin spots are moved by the expected movement vector, therefore moving them closer to the expected position of the target spots. This allows for a much smaller initial search radius, mitigating the issue of spurious tracks that are initiated in the wrong direction and must be terminated after 1 or 2 steps. The presence of these artifact tracks also impedes the initiation of the true tracks, therefore some visually very clear cases are ignored. After determining the relation between an origin and a target spot, the tracking can then proceed using the unmodified Kalman filter.