R1:2931cbcb55fb

Exit instead of throw from reparse.php without commits

Summary: I need to run this in `xargs`.

Test Plan:
$ echo 'E' | xargs -n 1 ./reparse.php --message --all

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4094