Clean up Maniphest transaction rendering a bit more

Summary:
Ref T2217. This partially retreads the ground from D7115.

  - We're rendering silly transactions about descriptions when creating tasks. Hide those.
  - Move the "created" transaction back to status. This fixes two things that are otherwise more of a mess than I'd anticipated:
    - It fixes Reports without making a mess (see <https://github.com/facebook/phabricator/issues/395>).
    - It renders old transactions properly (i.e., "created" instead of "reopened" for tasks older than the migration).
  - Be explicit about action strength, so emails always say the most important thing in the subject.

Test Plan: Created and edited tasks, looked at resulting transactions, saw a cleaner transaction record.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2217

Differential Revision: https://secure.phabricator.com/D7141
Adjust keys for new Differential inline comment table

Summary:
Ref T2222. This sequences //before// D7139 and sorts out keys on the table. In particular:

  - There was a fairly silly `draft` key modeled after Pholio; drop it.
  - Add a `revisionPHID` key. This is queried mostly-transitionally on the revision view screen.
  - Add a `changesetID` key. This is queried by a bunch of interfaces that want more surgical results than `revisionPHID` provides.
  - Add an `authorPHID, transactionPHID` key. This is queried on the list interface to find pending drafts.
  - Add a `legacy` key. This is queried by the feed publisher.

Test Plan: Used the query analyzer to hit all (I think?) of the pages, saw keyed queries.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2222

Differential Revision: https://secure.phabricator.com/D7140
Fix spacing on Diff headers

Summary: Adds some padding to the right

Test Plan: Looked at a diff

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, aran

Differential Revision: https://secure.phabricator.com/D7143
Allow editPolicy, viewPolicy, and repositoryPHID to be edited from the web UI in Differential

Summary: Ref T603. I think T2222 is fraught with peril so I'm not going to try to sequence it ahead of T603 for Differential. Provide access to policy controls in Differential's edit view.

Test Plan: See screenshot.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D7142
Allow revisions to be queried by repository

Summary: This isn't too useful most of the time since we don't automatically populate this data yet, but works fine.

Test Plan: See screenshot.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7144
Herald - add support for "content source" conditions

Summary: ...and deploy on Maniphest. Ref T1638.

Test Plan: created a herald rule to be cc'd for tasks created via web. made a task via web and another via email and was cc'd appropriately. edited the herald to be cc'd for tasks created via not web. made 2 tasks again and got cc'd appropriately

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, aran

Maniphest Tasks: T1638

Differential Revision: https://secure.phabricator.com/D7145
Maniphest + Herald - add support for assigning tasks and adding projects

Summary: This ends up living in HeraldAdapter even though its "task only" stuff. Reason being There are 4 or 5 functions that have little hooks; see diff. Ref T1638.

Test Plan: made a rule to assign tasks to me if made on web - great success. made a rule to assign tasks to other guy and add a project if title contained "foobar" - great success, including some confusion as ther two herald rules fought each other for task ownership.

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, aran

Maniphest Tasks: T1638

Differential Revision: https://secure.phabricator.com/D7146