jquery dimensions & offset: moving the local function 'num' to core, …

…so it can be safely used by both modules.

src/core.js

@@ -1359,3 +1359,8 @@ jQuery.each([ "Height", "Width" ], function(i, name){
 					this.css( type, size.constructor == String ? size : size + "px" );
 	};
 });
+
+// Helper function used by the dimensions and offset modules
+function num(elem, prop) {
+	return elem[0] && parseInt( jQuery.curCSS(elem[0], prop, true), 10 ) || 0;
+}

src/dimensions.js

@@ -20,8 +20,4 @@ jQuery.each([ "Height", "Width" ], function(i, name){
 				num(this, "margin" + tl) + num(this, "margin" + br) : 0);
 	};
 
-});
-
-function num(elem, prop) {
-	return elem[0] && parseInt( jQuery.curCSS(elem[0], prop, true), 10 ) || 0;
-}
+});