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

Corrected AWH initial histogram size

The initial histogram size for AWH biases depended (weakly) on the force constant. This dependence has been removed, which increases the histogram size by a about a factor of 3. In practice this has only a minor effect on the time to solution. For multiple dimensions, the histogram size was underestimated, in particular with a combination of slower and faster dimensions. The, now simplified, formula for the initial histogram size is given in the reference manual.

Issue 3751