Pretty up the exception output in dev mode, refs T1022

Summary: Applies the same options as Ushahidi_Formatter_JSON.

Test Plan: Trigger an exception of some kind. Unauthorized access is easy.

Reviewers: aMoniker, sheesh, vladimir

Reviewed By: vladimir

Subscribers: spaudanjo, rjmackay, srutto

Maniphest Tasks: T1022

Differential Revision: https://phabricator.ushahidi.com/D468