Publish Doorkeeper object stories to JIRA

Summary:
Ref T3687. Publish stories into JIRA.

These need some voicing fixes, which maybe involves straightening out the feed code. For example, they're voiced in-context ("updated this revision") when they should be voiced out-of-context ("updated D123").

Generally, this is similar to the Asana stuff but a lot simpler since we don't need to do any state management.

Test Plan: {F57366}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3687

Differential Revision: https://secure.phabricator.com/D6892