Author: Nathan Nguyen
MDL-61537 assignfeedback_editpdf: Rotate PDF page
Add page rotation feature.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9432553b1ce8e09c26c59e5b6c0375ec64ddc028
http://github.com/moodle/moodle/commit/9432553b1ce8e09c26c59e5b6c0375ec64ddc028
+ 3.7 en [rotateleft,assignfeedback_editpdf]
+ 3.7 en [rotateright,assignfeedback_editpdf]