Core: Remove unused removeAttrs method

jQuery Core supports removing space-separated attributes since 1.7,
and its not used in the plugin anyway.

Fixes #1124

src/core.js

@@ -107,16 +107,7 @@ $.extend($.fn, {
 		}
 		return valid;
 	},
-	// attributes: space separated list of attributes to retrieve and remove
-	removeAttrs: function( attributes ) {
-		var result = {},
-			$element = this;
-		$.each( attributes.split( /\s/ ), function( index, value ) {
-			result[ value ] = $element.attr( value );
-			$element.removeAttr( value );
-		});
-		return result;
-	},
+
 	// http://jqueryvalidation.org/rules/
 	rules: function( command, argument ) {
 		var element = this[ 0 ],