osd mon: Track heartbeat ping times and report health warning

osd mon: Track heartbeat ping times and report health warning

Fixes: http://tracker.ceph.com/issues/40640
Signed-off-by: David Zafman <dzafman@redhat.com>
(cherry picked from commit 66d44e7f911a57100d650ad7df9445f88ec70140)

Conflicts:
	src/common/options.cc (trivial)
	src/mon/PGMap.cc (trivial)
	src/osd/OSD.cc (trivial)
	src/osd/OSD.h (trivial)
	src/osd/osd_types.cc (encode version difference)
	src/osd/osd_types.h (osd_stat_t location in file changed)

src/mon/PGMap.cc manually get rid of extra argument to checks->add
src/osd/OSD.cc rename ping_stamp to stamp for backport