Pull up r2181:r2229 to 2.3 branch. Includes fixes for:

#429 fix panning for odd size viewport
#478 Double clicking overview map expand/contract button zooms in Safari
#484 conflict between _addButton of MouseToolbar and PanZoom
#485 null pointer exception on CTRL+F5 in IE for WMS.Untiled
#486 add a few sanity checks to overview map
#489 requires tag incorrect in OverviewMap.js   
#498 overviewmap: rectangle has minimum height in IE



git-svn-id: http://svn.openlayers.org/branches/openlayers/2.3@2230 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/PanZoom.js

@@ -85,8 +85,8 @@ OpenLayers.Control.PanZoom.prototype =
         this.div.appendChild(btn);
 
         btn.onmousedown = this.buttonDown.bindAsEventListener(btn);
+        btn.onmouseup = this.doubleClick.bindAsEventListener(btn);
         btn.ondblclick  = this.doubleClick.bindAsEventListener(btn);
-        btn.onclick  = this.doubleClick.bindAsEventListener(btn);
         btn.action = id;
         btn.map = this.map;
         btn.slideFactor = this.slideFactor;