Summary: Updates "View Post" to use PHUIDocumentViewPro, updates calls to `newPage` and other minor modernizations. Edit Page updated to show proper document display as well. Ref T9545
Test Plan:
Write a blog post, edit it.
{F945897}
{F945896}
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin
Maniphest Tasks: T9545
Differential Revision: https://secure.phabricator.com/D14415
e4806631a5