Author: sam marshall
MDL-35141 Filelib: No icon for epub filetype
http://git.moodle.org/gw?p=moodle.git;a=commit;h=ed0f5a950713991b92e6ed69569c73603561796a
http://github.com/moodle/moodle/commit/ed0f5a950713991b92e6ed69569c73603561796a
+ 2.4 en [application/epub_zip,core_mimetypes]