Multi patch four

Warning: This patch series is 'breaking' meaning that pre-existing
sandboxes require some manual intervention after updateing.

To enable multi-tenancy we need the sandboxes to be 'self aware'.

Add the following lines to your config.yaml

sandbox:
  tempfile:sandbox
signoff:
  tempfile:signoff

Update your stats table to include the new 'instance' variable:

ALTER TABLE stats ADD instance VARCHAR(30) AFTER id;

That should be it.