Bugs fixed

Fixed exported libgromacs CMake target

Update the exported libgromacs CMake target to not depend on non- existing include paths and add GMX_DOUBLE define to interface definitions. The target now gets exported into the Gromacs namespace.

Issue 3468

Fixed unsolicited changing of atom names in pdb file

Remove functions to change atoms names when reading and writing pdb files. This affected naming of H atoms in particular.

Issue 3469