Use ActionManager to register in-template actions
Merge pull request #5342 from mmun/action-manager

Use ActionManager to register in-template actions
Remove deprecated action lookup as methods on controller.

The older lookup in the root of the controller has been deprecated
since late-2013, and is a frequent cause of annoyance for newcomers.
This PR removes the deprecated lookup completely.

This has been discussed with the full core team.
Merge pull request #5347 from rwjblue/remove-deprecated-controller-action-support

Remove deprecated action lookup as methods on controller.