Added collection migration capability

Enabled migration of a collection one document at a time and working at
the JObject level.
Added xunit binding redirect
Revert "Added xunit binding redirect"

This reverts commit 214ce800edb4b0cf85c98357924199ff083fd00f.
I think I'll add the binding redirect back again!
Fixed tests by using the migration directly.
Changed collection update syntax to use verbs.
Merge pull request #2 from seankearon/master

Collection migrations, thanks Sean Kearon!