[work in progress] 1120671 - missing operation from reaper and monthly tasks

I also added documentation about these tasks
If I'm reading this correctly, I think this will create a TaskStatus record for every task that the scheduler dispatches. That is definitely not what we want.

What might be a better solution is to follow a model like this: https://github.com/dkliban/pulp/blob/1120671/server/pulp/server/tasks/repository.py#L172

In that case, we can't derive the appropriate tags in advance. So we have the ``pulp.server.tasks.repository.publish`` task that gets queued. When it runs, it generates the tags and queues the actual publish operation, which is ``pulp.server.managers.repo.publish.publish``.

So for this case, we could create a new intermediate task whose only job is to add these special pulp-specific tasks.

Also, I think it's likely still wrong that the ``publish`` and ``sync_with_auto_publish`` tasks here have ``base=Task``: https://github.com/dkliban/pulp/blob/1120671/server/pulp/server/tasks/repository.py#L171

That may or may not explain some of the task list entries that are missing information.

Let's talk through this in the morning and re-evaluate the approach.