Merge release-5-0 into master

Merge release-5-0 into master

Conflicts:
    src/external/gmock-1.7.0/CMakeLists.txt
        - took both changes on the same line
    src/gromacs/gmxpreprocess/calc_verletbuf.c
        - took both changes on the same line
    src/gromacs/mdlib/nbnxn_cuda/nbnxn_cuda_data_mgmt.cu
        - discarded temporary common.h hack from release-5-0 in favor of
          better solution in master
    src/gromacs/selection/nbsearch.cpp
        - resolved all conflicts in favor of master (were from a
          back-ported change)

Change-Id: I34190b704bcb1c020dcc2a3586a25620fd3c3ccf