Switched jQuery() to represent jQuery([]) instead of jQuery(document).

src/core.js

 // Define a local copy of jQuery
 var jQuery = function( selector, context ) {
 		// The jQuery object is actually just the init constructor 'enhanced'
-		return arguments.length === 0 ?
-			rootjQuery :
-			new jQuery.fn.init( selector, context );
+		return new jQuery.fn.init( selector, context );
 	},
 
 	// Map over jQuery in case of overwrite

test/unit/core.js

@@ -16,7 +16,7 @@ test("jQuery()", function() {
 
 	// Basic constructor's behavior
 
-	equals( jQuery().length, 1, "jQuery() === jQuery(document)" );
+	equals( jQuery().length, 0, "jQuery() === jQuery([])" );
 	equals( jQuery(undefined).length, 0, "jQuery(undefined) === jQuery([])" );
 	equals( jQuery(null).length, 0, "jQuery(null) === jQuery([])" );
 	equals( jQuery("").length, 0, "jQuery('') === jQuery([])" );