IE treats non-assigned zIndex values as 0. children of an element with a

zIndex set to 0 will always be below children of an element with a zIndex
set to 100. Because VirtualEarth sits outside the ContainerDiv, its maps were
always showing up over things contained inside the container div, such as 
markers. Acceptance test for this is to visit ./examples/ve.html and see if
the marker displays (should be over barcelona). IE, Firefox and Safari now
pass this acceptance test.


git-svn-id: http://svn.openlayers.org/branches/openlayers/2.0@1331 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Map.js

@@ -134,6 +134,8 @@ OpenLayers.Map.prototype = {
         // the layerContainerDiv is the one that holds all the layers
         id = div.id + "_OpenLayers_Container";
         this.layerContainerDiv = OpenLayers.Util.createDiv(id);
+        this.layerContainerDiv.style.zIndex=this.Z_INDEX_BASE['Popup']-1;
+        
         this.viewPortDiv.appendChild(this.layerContainerDiv);
 
         this.events = new OpenLayers.Events(this, div, this.EVENT_TYPES);