Adding counters, and fixed the gitignore

The analyses now create a file containing yields in workdir/stat/<anName>/<cfgName>.dat

A summary of efficiencies is printed at the end of the MPAF execution, for each dataset, and for several scheme of efficiencies :
- global (default instance of counter, used for the main analysis workflow)
- additionals (name given by the user, used for e.g. lepton efficiency during the selection. For an example, look for "vetoLepSel" in SUSYSSDL.)

Three new functions added :
-counter(string, string="global") simple counter, first input is the tag identifying the level of selection int he analysis. Usually used to define the first yield or denominator. Second input is the scheme of analysis (default=global)
- makeCut (templated) and makeCut (not templated, working with a boolean). do the selection, and count in the same time. able to do proper bracketing cuts. Recommended to use it if a counter is needed right after that selection step.

N.B : efficiencies and yields created only contains the pileup weight, proper lumiXS normalization will be set in place in next future.