Enable Evil^H^H^H^HJSON for PHP on Ubuntu 13.10

Summary:
Good news. Starting with Ubuntu 13.10, Phabricator can legally be used by evil dictators, mad scientists, and toxic derivative creators.

The JSON implementation prohibiting evil (http://www.phoronix.com/scan.php?page=news_item&px=MTQ0MTY) was ripped out and replaced by the Evil-friendly PHP license: https://github.com/remicollet/pecl-json-c/blob/master/LICENSE

Test Plan: ran the shell script, Phabricator no longer fails with "Call to undefined function json_decode".

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7878