improvements in the form of reduced memory use and lower element creating costs,
hopefully making the OpenLayers code more usable in internet explorer as well
as less of a memory hog in Firefox and other browsers. Additionally, a buffer
is available around the main map grid which allows tiles to be loaded outside
of the viewing area for faster dragging.
git-svn-id: http://svn.openlayers.org/trunk/openlayers@1137 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
