#13 geIconStyle's hotSpot element has incorrect default values.

According to Google's KML 2.1 documentation the hotSpot element in an IconStyle should have the following defaults:

<hotSpot x="0.5" y="0.5" xunits="fraction" yunits="fraction">

ge-kml currently defaults to the following:

<hotSpot x="0" y="0" xunits="pixels" yunits="pixels">