Added handling for client-side rendering to parse JSON if not automatically done.

Summary: Addressing the issues raised in T18 and T19.

Test Plan: N/A, seems to only occur on the actual site which runs behind Nginx.

Reviewers: Sabre070

Reviewed By: Sabre070

Maniphest Tasks: T18, T19

Differential Revision: http://phab.tychaia.com/D2