Author: Tim Hunt
MDL-48008 gradeimport_xml: report errors usefully
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c268bbc9e67635bf36349d86e4d1226cbf46a224
http://github.com/moodle/moodle/commit/c268bbc9e67635bf36349d86e4d1226cbf46a224
+ 2.7 en [errorduringimport,gradeimport_xml]