Create a process to assist pull server recovery if it is being rebuilt

[leshkinski]

To help with situations where the pull server needs to be rebuilt in-place, we need backups of the original pull server and client registration certificates restored on to the new server.

In addition, client re-registration process must be solved so that when the newly re-built pull server is online, its NodeData, client cert store and mof files are regenerated/re-populated correctly. This is related to issue #10