Author: Jamie Pratt
MDL-47494 ddmarker: NOBUG implemented the highlighting of drop zones with no drag hit
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e47c7eaec2bdeea05f918e63e130c76906c20d1a
http://github.com/moodle/moodle/commit/e47c7eaec2bdeea05f918e63e130c76906c20d1a
+ 3.0 en [followingarewrong,qtype_ddmarker]