This is the final change for the new actions framework, covering the

extension hooks and unit tests.
I've repurposed the old ActionHook (which was just used as a generic

base class) to be the new entry point for actions. This simply takes a

list of BaseAction instances and handles registering and unregistering

as appropriate.
The old legacy action hooks have been updated to translate the

dictionary definitions into BaseAction instances, which are then passed

upward to the ActionHook base class. These are all now treated as

deprecated, and will warn appropriately.
This also fixes up a variety of issues discovered with the unit tests.

Built an extension that used all of the hooks, both the modern and

  legacy. Saw that everything worked appropriately.
Ran python unit tests.
Ran js-tests.
Built codebase and manual documentation and checked all related

  pages for content and spelling.