Fixes #56

As a result, Internal Events were subject to the queue limit, when they shouldn't have been. Explains why the force-publishing failed for at least one beta tester.

If an event has no callbacks hooked to its action, skip it

Filter is available to bypass this

Fix timeouts on event-level locking

Setting one in minutes and the rest in seconds is just going to cause issues, such as in f21fdc8d.

Add event-level locking

Remove legacy scheduled event cleanup

Any sites running the plugin would be cleaned up by now, making this cruft.

Fixes #62

Miscellaneous and trivial CLI improvements

Corrects a bug introduced in ad4a5420
Fixes #67

Fixes #40

Fixes #47

Also stops the command from displaying an empty table if there are no events for the page

Fixes #67

Reduce number of posts processed by each run of our Internal Events

The events run frequently enough that smaller batches are fine. Will also reduce load from these events until #63 is addressed.

Will allow the locks for one-off events to naturally expire, while also guarding against long-running events that die before freeing their locks

Just like Internal Jobs, they shouldn't bother the lock status

Update job that cleans up unneeded data, adding coverage for a transient we don't use

Fixes #50

CLI commands to delete or run events, and deal with locks

Provide relative run-time when running an event prematurely

Introduce command to run an event on demand