R1:58b6e2cac641

Convert AphrontDialogView to safe HTML

Summary:
Done by searching for `AphrontDialogView` and then `appendChild()`.

Also added some `pht()`.

Test Plan: None.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4882