====== Add extra-info field for LHCb::Tracks ======
===== Problem =====
When trying to access the extra-info field for a track, it may happen that it is not filled. This can get annoying f. ex. when dumping an nTuple, where only the standard value is filled, like:
<code>
tuple->column( head+"_TrNExpectedTT", track->info(LHCb::Track::nExpectedTT, -100.) ); 
</code>

===== Solution =====
The extra-info field is filled in the algorithm ''TrackAddLikelihood'' in ''TrackAddExtraInfoSeq''.
  * Check if the algorithm is really in this sequence.
  * If yes, but the fields are still not filled, give the inputLocation of the Tracks you want the information from manually, f.ex.
<code>
TrackAddLikelihood("TrackAddLikelihood").inputLocation = "Rec/Track/Forward" 
</code>
Note the LOWERCASE ''i'' of ''inputLocation''!

This should solve the problem.