Enable finding element or elements by type array

It'd be great if @sebv could review this. I verified it works on UICatalog.

My goal is to filter elements by type array, visibility, and only first. Then I can use predicate selectors on the element list and avoid using xpath.

--

> Add _elementOrElementsByType
>
> Usage Example:
>
 find_element :uiautomation, %Q($.mainWindow()._elementOrElementsByType(["UIAStaticText"], true, true))
find_elements :uiautomation, %Q($.mainWindow()._elementOrElementsByType(["UIAStaticText"], false, true))

Fix #32