jzaefferer/jquery-validation — pull request #852 by DelvarWorld (2013-08-15 04:56:06+00:00)
Title: Triggering success on optional but have other successful validators

Addresses issue #851. The comment in the code itself says "when there
are no other rules" but does nothing to enforce that comment.

This uses a jquery map function to count object keys, as Object.keys
does not work in < IE9. Taken from http://stackoverflow.com/questions/5533192/how-to-get-object-length-in-jquery