Merge branch release-5-0

Merge branch release-5-0

Implemented usingGpu() for use by md.cpp in the new rerun behaviour,
because nonbonded_verlet_t is now opaque in master
branch. Unfortunately there is not yet a good home for its
implementation, so it's next to the "constructor" in forcerec.cpp.

Fixed typo in copyright header of gmx_detect_hardware.cpp

Conflicts:
	src/gromacs/mdlib/forcerec.cpp
Added gromacs/simd/simd.h to the right place, per fix in release-5-0

	src/gromacs/mdlib/tpi.cpp
Added gromacs/simd/simd.h to the right place, per fix in release-5-0

	src/programs/mdrun/runner.cpp
Trivial conflict from introducing GPU-usage variables
on line before removal of time variables.

Change-Id: I6157d962d183fae4e6874057da01f44ce10e733c