message: reintroduce clipboard events
diff: {
  "mixins": {
  "mixin": {
  + "DocumentAndElementEventHandlers": {
  + "events": {
  + "event": [
  + {
  + "name": "copy",
  + "type": "ClipboardEvent"
  + },
  + {
  + "name": "cut",
  + "type": "ClipboardEvent"
  + },
  + {
  + "name": "paste",
  + "type": "ClipboardEvent"
  + }
  + ]
  + }
  + },
  "GlobalEventHandlers": {
  "events": {
  "event": [
  