Number pad digit keys not handled properly

[adegruchy]

When passed through the normalizedKeyForEvent function, key events for number pad digits are incorrectly transformed because the keyIdentifier property for the event has the same Unicode value as a-i.

The keyIdentifier property is deprecated and non-standard (API), so this check should be removed, or at least placed below the check for the keyCode property.

If the transformKeyIdentifier check is put below the transformKeyCode check, an issue with the transformKeyCode function becomes apparent when testing number keys. The keyCode parameter should have 48 and 96 subtracted from it for top row numeric keys and number pad digits respectively, not the other way around.

I've created a pull request for this issue.