Integrate constant-pH code
The constant pH code is currently in a prototype state in a branch. It is feature complex and performant, full GPU and DD support is present. To integrate this into GROMACS master we need to:
- Clean up the internals
- Add electrostatic potential flavors of all kernels (the current implementation always calculates potentials which leads to overhead without constant-pH.
- Ideally this should be an MD module, but then MDModules needs to support callbacks for changing force field parameters (charges) and for integration
- Move the output from separate files to energy blocks
- Potentially restructure the user input.
Note that the current constant-pH code is already completely encapsulated in a class with a minimal interface and all input is contained in t_inputrec.