Have the basics of a redis migration script in place.
We're almost there.
Delay the terminate action to avoid race conditions.

This only appears in the tests; What happens here is that the satus has already
changed state when the websockets reads it and so a wrong value is returned.
Remove console.log calls
return the right count when doing a delete
Fix some documentation
@natim review.
Remove the setTimeout in the tests
Add support for redis hash migrations.
Add support for MULTI.

MULTI commands will be all run independently rather than be done in
a transaction if the migration backend is activated.
Fix bad registration implementation
Merge pull request #246 from mozilla-services/redis-migration

Redis migration