Data migration completed for time allocations

Instance is straight-forward, Volume loops through every
available identity to assign volumes (Becuase no user information
is given from the API) and machines is the most complete
using a three part system to ensure that all machines have the correct
created_by and created_by_identity.

The machine parsing script has been pulled from the migration and added
 as a standalone script, I'm sure it will come in handy some day.
	modified:   core/migrations/0011_build_created_by_identity.py
	new file:   scripts/update_euca_machine_createdby.py