Sprout - appliance spring

Django/celery based appliance spring caretaker.

* Configure templates
* Deploy appliances on-demand
* Keep a pool of spinned appliances
* Spread the appliances across providers

More informations in the MOJO document I posted recently.
If `appliance_id` is only ever used for sprout, the signature of this really should be `def __init__(self, config, slaveid, base_url, zmq_endpoint, appliance_id=None):`