[selection-api] Selection events for text controls (#53)

The current spec doesn't explain what needs to happen for `input` and `textarea` elements when the selection inside them changes.  Those selections are not associated with the `Selection` object for a `Document`, so we need to handle them somehow.

I think a nice way to extend the current spec to cover this case would be to dispatch `selectstart` and `selectionchange` to the `input` or `textarea` element itself when the selection inside them changes.  The reason why the `selectionchange` event needs to be dispatched to the element and not the `Document` is that the web page would otherwise be unable to detect which selection has changed.

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/selection-api/issues/53