GN: Added variables and procedures for reading hodoscope parameters found in:

xhodo.pos and xhodo.param
THcHodoscope generally holds:
- singular variables (i.e. central path through the spectrometer, min/max limits for the ADCs, TDCs, etc.)
- "padded arrays" (i.e. look at the plane with the most scintillators, allocate and array that has max_no_scint * no_of_planes - these are mostly found in the .param file)
THcScintillatorPlane generally holds:
- simple variables containing plane-specific info (z-position, scintillator size and spacing)
- arrays sized appropirately for the specific plane (i.e. individual x (or y) positions for all scintillators in a plane, signal propagation speed in the paddle, etc.)