Author: danghieu1407
MDL-60910 ddimageortext: Create option for using transparent pictures
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6f956ce910510ded2cf94e9f171c82ba5f921eba
http://github.com/moodle/moodle/commit/6f956ce910510ded2cf94e9f171c82ba5f921eba
+ 5.0 en [dropzonevisibility,qtype_ddimageortext]
+ 5.0 en [dropzonevisibility_help,qtype_ddimageortext]
+ 5.0 en [dropzonevisibility_hideoption,qtype_ddimageortext]
+ 5.0 en [dropzonevisibility_showoption,qtype_ddimageortext]
+ 5.0 en [dropzonevisibilitydesc,qtype_ddimageortext]