* Ported audit for 'AriaOwnsDescendant' from aria-toolkit.
 * Added unit tests for 'AriaOwnsDescendant'.
 * Gave IE11 some love, all errors fixed and now only one unit test failing.
 * Did a significant refactor on my earlier work to try to better fit the style of the existing codebase.
 * Fixed several random little typos that caught my eye, such as missing semicolons.