Skip the "Too Many Errors" error that is raised by JSHint.

Summary: If JSHint encounters //too many// errors (by default, more than 50) errors, then it quits prematurely and raises an additional (rather unhelpful) "Too Many Errors" error. We should just ignore this additional error.

Test Plan: Added a test case.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9693