R1:b85283105ece

Phriction - restore diff link

Summary: Fixes T6472. I was curious to see how many reports we'd get but we didn't get any I know of... Still, this is a nice convenient link.

Test Plan:
edited a wiki doc title + body. ran /bin/mail to see the body and liked what I saw

```TEXT BODY
btrahan changed the title from "new title is a good thing" to "new title is a good thing asdsadsadsadsada".
btrahan edited the document content.

DOCUMENT DIFF
http://phalanx.dev/phriction/diff/36/?l=3&r=4

DOCUMENT DETAIL…