osd: use dmclock library client_info_f function dynamically

[bspark8]

Use dmclock library client_info_f function dynamically to be able to apply QoS parameter changes at run-time in Ceph and brings in related dmclock library changes.

[ivancich]

Can we rebase this on current master? That this PR seems to be modifying files below src/dmclock is a red flag (since we should be modifying the dmclock library directly and then pulling those changes back into ceph). However, I'm guessing some of these changes correspond to
ceph/dmclock#24 and therefore have been pulled into ceph recently. A rebase will help us see what the actual changes are.

[bspark8]

I finished rebase as you said.
In order to use the client_info_f function dynamically in Ceph, I modified the template parameter in mClockPriorityQueue.h to true.
The dmClock library pull process is skipped because the dmClock latest source (including ceph/dmclock#24) already has been pulled into the current Ceph master.

Thank you.

[ivancich]

Looks good. Let's run this through the QA to make sure it doesn't introduce problems.

[ivancich]

Just waiting for QA.

[yuriw]

http://pulpito.front.sepia.ceph.com:80/yuriw-2017-09-25_22:30:36-rados-wip-yuri-testing3-2017-09-25-2007-distro-basic-smithi/

http://pulpito.ceph.com/yuriw-2017-09-26_15:27:59-rados-wip-yuri-testing3-2017-09-25-2007-distro-basic-smithi/