Changed the marker and zoom behavior. If mouse hovers over the marker, show info window. If mouse leaves the marker, close info window. If mouse clicks the marker, zoom in and show info window. If view is on zoom level 14 and mouse clicks the marker, zoom out to zoom level 2.
Removed some commented-out lines.
Keeping infowindow open on click, and resetting to user's choice of zoom on second click.
Defined some constants for zoom values.