tools: Add pg log trim command to ceph-objectstore-tool

tools: Add pg log trim command to ceph-objectstore-tool

Add test script that verifies the command in qa/standalone/osd

Fixes: http://tracker.ceph.com/issues/23242
Signed-off-by: Josh Durgin <jdurgin@redhat.com>
Signed-off-by: David Zafman <dzafman@redhat.com>
(cherry picked from commit b01e4ea5e2c1d2e9e997f53621aba73a7f7c9241)

Conflicts:
	src/tools/ceph_objectstore_tool.cc
		Different ops
		Need ObjectStore::Sequencer
		Use apply_transaction()
	qa/standalone/special/ceph_objectstore_tool.py
		Different ops

(cherry picked from commit b055cde916d00014e0d148f129934216f29252d4)

Conflicts:
	src/common/legacy_config_opts.h src/common/options.cc
        	Use src/common/config_opts.h in Jewel
	src/test/ceph_objectstore_tool.py (different ops)
	src/tools/ceph_objectstore_tool.cc (different ops, no PastIntervals)
	src/test/osd/repro_long_log.sh
		Moved from ../qa/standalone/osd
		Use Jewel ceph-helpers.sh location
		No ceph-mgr in Jewel
		Single test that creates 51 write entries and trims to 30