Set up basic outline for how fit parameters will now be defined:
   - initialised in Options.h within Config struct
   - set to defaults in Options.C::LoadDefaultSettings()
   - overwritten with value from config file.
Implemented first few values in this fashion.
All fit parameters are now set to sensible defaults and then overwritten with values found in config file.
Same for charge spectra properties: number of bins, maximum.
Same for charge integration.
Warning generated if item in config file is not recognised.
Some unused #define items removed.