mark a few functions as private

git-svn-id: http://svn.openlayers.org/branches/openlayers/2.0@1286 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Grid.js

@@ -150,6 +150,8 @@ OpenLayers.Layer.Grid.prototype =
     },
     
     /**
+     * @private
+     * 
      * @returns A Bounds object representing the bounds of all the currently 
      *           loaded tiles (including those partially or not at all seen 
      *           onscreen)
@@ -170,7 +172,7 @@ OpenLayers.Layer.Grid.prototype =
     },
 
     /**
-     * 
+     * @private
      */
     _initTiles:function() {
         var viewSize = this.map.getSize();