fix firefox bug in videoautoplay, ensure check happens after a tick

fixes #1095

few things done here.

1. Removed incorrect `notes` section (must have copied it from the animation test - thats embarrassing)
2. firefox was erring out because it requires removeEventListener to be called with the listener function
3. delay the actual listener attachment for a tick. this fixes the inaccurate test results for me everywhere. seems like  there wasn't enough breathing room in some situations between adding the element, and the listeners firing
4. firefox triggers a `playing` event when the time is === 0, so I added an optional argument that sets the test to true if it is called from the `playing` event listener.