STYLE: Refactored cp -> Cp

Needs dTarget data member in KinematicParcel.

Some functions in InjectionModel no longer const.

Squashed merge of particleInteractions up to
commit e7cb5bcf0315c359539ef1e715e1d51991343391

pi -> angularMomentum
tau -> torque

to KinematicParcel incorporating latest master branch changes.

- removed support for total enthalpy
- much cleaner/improved code for transfer terms

- Using parcel chemical enthalpy to update cloud chemical enthalpy transfer
  instead of total parcel enthalpy.
- Added functionality to allow enthalpy transfer to be user-controlled,
  either using latent heat, or instanteous enthalpy difference

- added (cumulative) contributions due to transfer of mass, mom and energy when
  evaluating cell properties

    - reacting now single phase, multi-component
      - new phase change sub-model
    - new reactingMultiphase = multi-phase, multi-component