"Using 3rd-Party Libraries" guide updated

docs/guide/using-3rd-party-libraries

@@ -80,9 +80,9 @@ class Yii extends \yii\BaseYii
 {
 	public static $classMap = [];
 	public static $enableIncludePath = true;
-	private static $_aliases = ['system'=>YII_PATH,'zii'=>YII_ZII_PATH]; // alias => path
-	private static $_imports = [];										// alias => class name or directory
-	private static $_includePaths;										// list of include paths
+	private static $_aliases = ['system'=>YII_PATH,'zii'=>YII_ZII_PATH];
+	private static $_imports = [];
+	private static $_includePaths;
 	private static $_app;
 	private static $_logger;
 
@@ -109,6 +109,10 @@ Yii::$classMap = include($yii2path . '/classes.php');
 Yii::registerAutoloader(['Yii', 'autoload']); // Register Yii2 autoloader via Yii1
 ```
 
+Note: while copying methods you should NOT copy method "autoload()"!
+Also you may avoid copying "log()", "trace()", "beginProfile()", "endProfile()"
+in case you want to use Yii2 logging instead of Yii1 one.
+
 Now we have 'Yii' class, which suites both Yii 1.x and Yii 2.x.
 So bootstrap code used by your application will looks like following: