Adds recent change list to summary

The changes button on the left of the deployer bar can now be used to show
recent changes in the summary panel. This largely reuses the logic of the
deploy confirmation functionality, with some refactoring to allow both actions
to coexist.

There are still changes necessary to for this work to be done:
* The recent changes should be rendered in the confirm deploy version, in a
  collapsed summary panel that can be expanded.
* There is still a lot of visual polish necessary to match the mockups.

QA:

with :flags:/il/mv/

1) Deploy a service
2) Click "changes" on the left of the deployer bar.

You should see a list showing that the service has been added and a unit for
that service has been added. You should not have deploy buttons or other
controls.

3) Click "changes" again.

The the summary panel should close.

4) Click deploy

You should see the usual deploy confirmation; it should all work normally.