Added ADC Error Flags for ScintillatorPlane.cxx class

-Added fAdcTimeWindow Min/Max to THcHodoscope.cxx (.h)
-Added fAdcTimeWindow Min/Max to THcScintillatorPlane.cxx (.h)
-Initialized loop over number of hits inside the FillDynamic_Pedestal() method
-added some variables in the THcScintillatorPlane.cxx Dynamic Pedestal Method
-Added loop over adc_pos and adc_neg hits, and required the hits to fall
within fAdcTimeWindow Min/Max
-Added the requirement of at least a valid (adc && tdc) on either end of a bar
-re-defined boolean operator for adc_pos/adc_neg to be True if  they passed the errorflag and timeCUT requirements in the fADC_Dynamic Pedestal method.
-- deleted adc_pos/neg initial definitions, and set their initial values to -999.