Merge branch origin/release-5-0

Merge branch origin/release-5-0

Conflicts:
	CMakeLists.txt
Bumps to version information not needed in master branch,
so not added.

	docs/install-guide/install-guide.md
Incorporated new docs for static binaries

	docs/old-html/online/mdp_opt.html
Incorporated new docs for soft-core

	src/external/boost/README
Incorporated new hint about compiler warnings to
suppress if ever bundling an updated version of Boost
smart pointers.

	src/external/gmock-1.7.0/CMakeLists.txt
Incorporated new machinery for suppressing
no-unused-variable GCC 5 warnings in GMock source.

	src/gromacs/gmxpreprocess/grompp.c
Recent bug fix in t_state touched same lines as
changes in master branch to remove file type TPX
and the need to pass a parameter to a pull-start
function, so made both changes together.

	tests/CMakeLists.txt
Changes to the developer-download of regressiontests
and the way that is implemented touched adjacent lines,
so made both changes together.

Change-Id: I8fb94c3a55893f6bc76d7cf6f33378f94cacf618