TrackCountingComputer update for displaced jets

Added functionality for tagging displaced jets using the b-tagging track counting computer at HLT. For use in confDB.

Added a minimum impact parameter cut to remove background events which low displacement but high Impact parameter significance. 

Added an option to sort tracks using unsigned impact parameter significance. When the a long lived particle (X) decays to two jets and the X is not significantly boosted, one of the jets flight path can be opposite that of the (X). This produces high negative values of Impact parameter significance.

Fragments updated and existAs statements added to produce old behavior.