Add Flock and FlockManager classes

The first represents s flock starting at m_startTime and ending at m_endTime (if less of equal the minimum flock
length), with trajectories m_trajectories.
The second performs operations on flocks and store them

Added some methods to Trajectory class, that will be needed by those classes, like:
    * mergePoints: Merge points from the same trajectory from different times
    * clearFirstPoints: when we find a flock we start looking for a new one on the subsequent start time, so we must
      clear the points from that time

Signed-off-by: Thiago de Barros Lacerda <tbl2@cin.ufpe.br>
[Debug] add dump functions and improve others

Signed-off-by: Thiago de Barros Lacerda <tbl2@cin.ufpe.br>
Early return if the points to process number is smaller than the number of trajectories per flock

Signed-off-by: Thiago de Barros Lacerda <tbl2@cin.ufpe.br>
debug
patch