[WIP] Run ansible in a crontask on service hosts

This should help illustrate my mailing-list conversation wondering exactly how we should accomplish this.

Because this won't work well in development (it will always look at
prod-hosts), it's easily disabled with no_ansible_pull=true in the
inventory.  Fixes #3089.
On Sat, Dec 13, 2014 at 08:51:19PM -0800, Sean Kelly wrote:
> > @@ -0,0 +1 @@
> > +{{ vault_password }}
> 
> Per referenced elsewhere, can use the `copy` module with `src` option.
With `content` option.

-- 
Misha