initial version computeHiggsPtUncertaintyParameters

Work in progress. Something is different in our lfv ggh samples.
In the SM ones (for example 160655) I can see a h with status 62
and the number of truth jets is ~ the same as indicated in the
reweigthing instructions.
However, in our lfv samples I cannot see the h with status 62,
and the number of truth jets seems to be larger (before and after
the removal of the ones overlapping with the higgs decay products).
To be investigated.
SusyNtMaker::computeHiggsPtUncertaintyParameters: pick correct higgs

The instructions for the higgs pt reweighting
https://dgillber.web.cern.ch/dgillber/Higgs_pT_reweigh/ said that I
should pick the higgs with status `62`, which is missing from our lfv
samples because the decay was performed by EvtGen.
Rob confirmed that I shoul pick the one with status `999` instead.
bugfix SusyNtMaker::isPowhegLfvHiggsSignalSample
Merge pull request #34 from gerbaudo/store-h-truth-hlfv

Store h truth hlfv