Remove PCA_QUIET

Instead of exposing this to all callers of parse_common_args(), make the
command-line runner only execute the module on the master node in the
case help is being printed.  It should be quite rare that anyone runs -h
with multiple nodes (which is the only case this nowadays affected), so
this doesn't need an extra flag that callers need to be aware of.

Change-Id: I0a0b76d358bd7db283e5244c49acbd4a40d7af6f