Various fixes

based on #12 from @gpetruc

1) when storing individual trigger bits, remove the stars in the end  
2)  add Jet leadingTrack and leadingTrackPt (charged hadrond more than track in fact...)
3) as @cbernet asked, adding a config parameter to the TreeProducer so that the service looked for to provide the TFile is not hardcoded (default value is the old hardcoded name "outputfile")