Merge branch 'stable' into release

Author: fnoks

library.json

@@ -5,7 +5,7 @@
   "contentType": "Media",
   "majorVersion": 1,
   "minorVersion": 21,
-  "patchVersion": 8,
+  "patchVersion": 9,
   "machineName": "H5P.InteractiveVideo",
   "author": "Joubel",
   "embedTypes": [