R1:e40f0e13c5dc

Implement PhutilRequest parser

Summary:
If D6277 is the way to go, then this will be it's implementation.

Depends on D6277

Test Plan: Keep using the site

Reviewers: epriestley

CC: aran, Korvin

Maniphest Tasks: T3432

Differential Revision: https://secure.phabricator.com/D6278