This is a huge commit.  Sorry.  Anyway, it adds the feature that allows for migrating objects in one spaces to another space.  And the process is fault-tolerant.  It's not ready to be merged yet, since there hasn't been much testing.
Add a mechanism to inform the coordinator about the completion of migrations
Fix bugs related to migration
Get rid of useless debug statements
Fix bug in deserializing integers
Add a test case for migration
Clean up
Bug fix
Delete a file that was accidentally introduced
Cleanup