Overlapping Objects might not render as expected

[rlingineni]

Images always show up on top when overlapping. This is because our XMLtoJSON parser doesn't preserve the order of elements, so we first analyze shape objects and then any images thereafter.

The current best solution is to set the shape background fill as an image to support overlapping.

Everything is rendered in the order of slide placement. So place elements that go towards the back first, and then put newer elements on top. Changing shape order probably won't work as expected.