Make PonderQuestionEditor use ApplicationTransactions

Summary:
Ref T3373. Make PonderQuestions editable and use transactions.

This temporarily disables some stuff:

• email;
• feed;
• comments;
• voting.

I'll restore those in followups and wait to land this until they're at least mostly back online.

The transactions themselves also need more string/color/icon work.

Test Plan: Created and edited questions. Viewed transactions.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3373

Differential Revision: https://secure.phabricator.com/D6601