Merge branch release-2019 into master

Merge branch release-2019 into master

Resolved Conflicts:
	cmake/gmxDetectCpu.cmake
	src/gromacs/gmxpreprocess/topshake.cpp
	src/gromacs/listed-forces/bonded.cpp
	src/gromacs/mdlib/nbnxn_cuda/nbnxn_cuda_data_mgmt.cu
	src/gromacs/mdlib/nbnxn_gpu.h
	src/gromacs/mdlib/nbnxn_ocl/nbnxn_ocl.cpp
	src/gromacs/mdlib/nbnxn_ocl/nbnxn_ocl_data_mgmt.cpp

This does not include the change to the MPI_COMPILE flags handling,
as the code in master has been reorganized in a way that is incompatible
to that.

Change-Id: Idb1da69ce68f3121442859e8cbe24495c7894726