Making improvement of Hcal Validation package

1. Improve some histogram binning
2. fix wrong TDirectory names in DAQOffline/Hcal
3. Update Zdc related relval code
Automatically ported from CMSSW_7_2_X #5285
They are used as default value to fill the mapEnergy_N which is only used to hold number of entries as of now. It's a silly solution, but it works. If this is a concern, I can make changes of the implementation.