Improve Asana API error handling in Doorkeeper

Summary:
Ref T2852. We need to distinguish between an API call which worked but got back nothing (404) and an API call which failed.

In particular, Asana hit a sync issue which was likely the result of treating a 500 (or some other error) as a 404.

Also clean up a couple small things.

Test Plan: Ran syncs against deleted tasks and saw successful syncs of non-tasks, and simulated random failures and saw them get handled correctly.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2852

Differential Revision: https://secure.phabricator.com/D6470
Add ApplicaionTransactions and a mutable view policy to Slowvote

Summary: Schema changes to modernize this app.

Test Plan: Ran schema changes, created a new slowvote. No real effects yet.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6453
Migrate Slowvote comments to ApplicationTransactions

Summary:
Move comments from the old table to ApplicationTransactions. Patch dances around which objects it uses since I intend to delete the comment table.

NOTE: This temporarily disables comment writes. I'll restore them shortly.

Test Plan: {F50166}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6454
Restore Slowvote commenting with ApplicationTransactions

Summary: Now it works like everything else does.

Test Plan: {F50168}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6455
Make slowvotes subscribable

Summary: Subscribing doesn't do anything yet, but you can subscribe!

Test Plan: {F50169}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6456
Move slowvote loading logic into Query class

Summary: Mostly straightforward. Also fixed a couple of error/darkconsole things.

Test Plan:
  - Created poll;
  - viewed poll;
  - voted in poll;
  - used `V6` and `{V6}` markup styles in poll.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6458
Make slowvotes tokeanble

Summary: gimmie dem tokens

Test Plan: {F50176}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6459
Make most slowvote fields edit transactionally

Summary: No support for responses yet, since they're more complicated, but put everything else on the transactions plan. This also prepares polls for editability, shortly.

Test Plan: {F50205}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6460
Allow most Slowvote fields to be edited

Summary: Just cheating on the hard stuff for now.

Test Plan: {F50207}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6461
Show snippet of vote description in vote summary

Summary: This is editable now.

Test Plan: {F50208}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6462
Share rendering code for embedded votes and vote detail

Summary:
We have two separate pieces of rendering code and both are pretty ugly. Move them toward being more reasonable.

This could no doubt be improved:

  - Getting a text style which was readable on both the dark and light bars was hard, maybe we should change the colors or maybe I am just bad.
  - Could probably benefit from actual competent design in general.
  - JS magic is temporarily ineffective, I'll restore that in the future.
  - Embed style is a little funky (margin/centering).
  - Could use a little cleanup.

Test Plan:
{F50226}
{F50227}
{F50228}

Reviewers: chad, btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6465