Adding instance support to the canary backend.

Now lists, return available hosts and instances. To perform info
or query commands, simply use host:instance_id as the id in the
URL string. The reason we still require hosts is that (for example
with migration) multiple hosts could have the data for the same
instance.

Change-Id: I33fb0265da617c26be5fba2121897b429d12c1ba
Don't depend on the gridcentric.horizon.api package.

This nukes the bizarre requirement and pulls out the full
extensions client into the canary source directly.

Change-Id: I6d8bb280dd932e020f6f62583fc528f41bd9e1f3
By: Tim Smith <tsmith@gridcentric.com>
Merge "Adding instance support to the canary backend."
Updated Horizon plugin to match Canary changes

Stopped XHR updates once graph is deleted

Cleaned up imports in tables

Change-Id: I4e3087f48a5fcae51b6c701520209f69764855d1
Remove extension from nova conf on uninstall, not upgrade.