Merge branch 'wip-4779' into next

Reviewed-by: Sage Weil <sage@inktank.com># Please enter a commit message to explain why this merge is necessary,

diff --cc src/mon/MonCommands.h
Simple merge

diff --cc src/mon/OSDMonitor.cc
Simple merge

diff --cc src/pybind/ceph_argparse.py
Simple merge