When creating a Phriction document, mark initial transactions as "create" transactions to fix weird email

Summary:
Ref T13289. When you create a Phriction document, you currently get an email with the whole new content as a "diff".

You also get extra transactions in the email and on the page.

This is because Phriction isn't on EditEngine and doesn't mark "create" transactions in a modern way. Get them marked properly to fix these obviously-broken behaviors. This can all go away once Phriction switches to EditEngine, although I don't have any particular plans to do that in the immediate future.

Test Plan:

• Created a new document, viewed email, no longer saw redundant "edited content" transaction or "CHANGES TO CONTENT" diff.
• Updated a document, viewed email, got interdiff.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13289

Differential Revision: https://secure.phabricator.com/D20548