Branch b1_4_mountconf

Branch b1_4_mountconf
b=9860
upgrading from 1.4.6 - don't copy the old client log, just the old mdt log.
Regen client log as osts/mdt re-register after upgrade.
This means that new clients won't know about all the old osc's that the mdt
knows about, so don't start them until after all servers are upgraded.
But this also means no frankenstein hybrid old/new client log, and we don't
need to know the client name.
Use the old uuids parsed out of last_rcvd for the upgrading servers.
We can go back to 1.4.6 with no action required.