removed all "processing event" statements and obsolete event counters
addresses http://eutelescope.web.cern.ch/issue/output-currently-processed-event-number-should-not-be-part-every-eutel-processor
fixed memory leak: TrackerHitImpl object created but neither used nor deleted
addresses issue eutelescope/eutelescope#14
fixed memory leak: hits added to fitted track need to be stored in LCIO collection as well and written to file
addresses issue eutelescope/eutelescope#14
fixed (small) memory leak: added a EUTelTrackFitter::Clear() method and implementation in EUTelGBLTrackFit to allow cleanup of object after Fit is done (without deleting the object)
addresses issue eutelescope/eutelescope#14
Merge pull request #22 from hperrey/master

Reduced verbosity of producers and fixed memory leaks in GBL producers