Reconcile run-on-login Windows settings

[hartmantis]

There's a checkbox in the Divvy app that modifies user-level registry entries, but the windows cookbook only does machine-level registry entries.

What happens if another user (without Divvy installed) logs in?

What if Divvy is enabled in both places?

This is icky. Either the app needs to be installed machine-wide or the windows auto_run resource needs to support user-level keys.

[hartmantis]

Fixed by #13.