Author: Sara Arjona
MDL-67795 contentbank: delete content API
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c0d615e8f911bd943fb87633d01683cd112c4b52
http://github.com/moodle/moodle/commit/c0d615e8f911bd943fb87633d01683cd112c4b52
+ 3.9 en [contentdeleted,contentbank]
+ 3.9 en [contentnotdeleted,contentbank]
+ 3.9 en [deletecontent,contentbank]
+ 3.9 en [deletecontentconfirm,contentbank]
+ 3.9 en [contentbank:deleteanycontent,core_role]
+ 3.9 en [contentbank:deleteowncontent,core_role]