Release build fails in PDB2GMX google tests
The failed build is here http://jenkins.gromacs.org/view/Release/job/Release_workflow_master/216/
I started bisecting it.
Make only mdrun report process ID
Recent change 367d003106 changed where mdrun reported the process ID,
but in so doing changed various tools to also report the process ID.
This made pdb2gmx tests non-reproducible.
Since the process ID is probably only of minor value to the user, and
probably only of value to users of mdrun, this change adds support for
allowing tools to choose to print the process ID while defaulting to
not reporting it.