Deployer bar fixes

1. Fixed deployer bar change notifications not appearing.
It looks like this was because someone was renaming variables and missed a few.

2. Fixed summary being hidden.
Instead of re-rendering the entire template it now just clears the contents of the element.

I also did a drive-by spelling fix of the `_hideChangeDescription` function name.

QA: Drag a service to the canvas. A notification of the action should appear in the deployer bar for two seconds and then disappear.