- corrected the number of samples used for peak integral to 9.
   This number will eventually have to be read from prestart event.
 - added explicit casts from Int_t to Double_t in several methods

This makes the code nicer and with less duplication in logic.

Along with that I had to correct all the call sites to the RawHodoHit in all the
classes that use it.

Added new class THcRawTdcHit.
RawShowerHit update.

The new class THcRawAdcHit is meant to represent the raw ADC hits. The
logic with dealing with ADCs has become quite complex now and it would
have to be multiplicated across all detectors that have ADC
channels. While this by itself is not such a big problem, fixing
possible bugs in multiple places is.

I also redesigned the THcRawShowerHit class to use the new
THcRawAdcHit. The redesign was due anyway, so I took the opportunity.

I also had to modify THcShowerArray and THcShowerPlane. They still
need some work to use the the new flash 250 data, but changes were
necessary anyway.

Minor fix 01.