Adjust getZoomLevel function to support fractional values.
Adjust getZoomLevel function to support fractional values.

Remove unnecessary cast in addMapZoomEndListener as View.getZoom()
already returns a double value.

sebasbaumh/gwt-ol3,TDesjardins/gwt-ol3,sebasbaumh/gwt-ol3,TDesjardins/gwt-ol3,sebasbaumh/gwt-ol3,TDesjardins/GWT-OL3-Playground,TDesjardins/gwt-ol3,TDesjardins/GWT-OL3-Playground,TDesjardins/GWT-OL3-Playground