ol-ext: Popup overlay

Display popup on the map.

• You can use classes to style the popup with a css (or choose an existing one).
• You can control the position of the popup top|center|bottom|auto - left|center|right|auto.
• The auto position lets the popup choose a good positioning according to the position on the map.
• The closeBox option adds a close button to hide the popup.
• The onclose option is a callback function when the close button is clicked.
• You can add a bounce animation effect when popup appear just by adding the popupoverlay.anim.css (see example)

You can add a mini vertical scrollbar to your popup using the minibar option.