Caching array length instead of accessing it with each iteration. r=crschmidt (closes #1636)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@7627 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Geometry/Curve.js

@@ -45,7 +45,7 @@ OpenLayers.Geometry.Curve = OpenLayers.Class(OpenLayers.Geometry.MultiPoint, {
     getLength: function() {
         var length = 0.0;
         if ( this.components && (this.components.length > 1)) {
-            for(var i=1; i < this.components.length; i++) {
+            for(var i=1, len=this.components.length; i<len; i++) {
                 length += this.components[i-1].distanceTo(this.components[i]);
             }
         }