Control: Implement resource to delete tenant tables

[wolpert]

The method is just stubbed right now.

There is lots here, since you have to call all the nodes to delete, which should be in parallel. Consider async actions too. This may take a bit to get right.

[wolpert]

Current changes working on:

1. Create a method on control for a node to say it deleted the table.
2. Update node to read the 'delete' request from etcd and delete the table, Ping control when done. Control remove the table entry from the db. Remove all if everything is cleared, including etcd.
3. Update control to set the delete request on the node range action, and delete the tenant resource from the etcd proxy.

[wolpert]

TODO: Need to delete the etcd entry from control when the node call delete.