position selected feature on top

This is not done, #100 (closed)

To get the marker to appear on top, decided to add an SVG tile layer to the map. We tried this with the canvas tile layer and it was not allowing you to click the markers beneath the top layer. The bottom layer is still a canvas vectorgrid layer. It looks like you cannot add only one tile layer, but we are only adding one marker to the top tile layer.

If anyone can think of a better way to do this feel free, but it seems to be working. Also we have noticed some strange behavior (intermittently) when changing the map extents. Sometimes the map bounces back and forth and never stops updating the map extents. Cannot reproduce this behavior consistently enough to test it.