Added a Copy Database Job for use in the new backup model

This job is simple, it copies databases. It supports using a fixed name (nuget-dev-0-v2gallery_failover) or a prefix with timestamp ("export_<em>timestamp</em>"). It always does a "fast overwrite" by copying to a GUID name, then renaming the old DB (if there is one), renaming the GUID name to the target name, and dropping the old DB. Of course, if there is no old DB (i.e. the timestamped-name case) it just does the rename.

And as a bonus, it doesn't use the SQL Admin account!

![happydance](https://cloud.githubusercontent.com/assets/7574/2858587/1cc5370e-d18b-11e3-9c73-be5938a63c3f.gif)