Property: closeDiv {DOMElement} the optional closer image
Property: contentDiv {DOMElement} a reference to the element that holds the content of the div.
Property: div {DOMElement} the div that contains this popup.
Property: id {String} the unique identifier assigned to this popup.
APIProperty: panMapIfOutOfView {Boolean} When drawn, pan map such that the entire popup is visible in the current viewport (if necessary). Default is false.
APIProperty: autoSize {Boolean} Resize the popup to auto-fit the contents. Default is false.