Git commits in Moodle 2.2.x by Matt Petro

commit 4befe7f5510448bab3bd572f354b65326c3f3db0
Author: Matt Petro <petro@engr.wisc.edu>
Date:   Fri, 19 Oct 2012 22:59:42 +0800
Tag:    v2.2.7

MDL-36025 qtype calculated: Fix handling of "-0"