Partially reverting some changes and improving the original content

Author: Sgoettschkes

book/internals.rst

@@ -22,7 +22,8 @@ on top of the previous one.
 .. tip::
 
     Autoloading is not managed by the framework directly; it's done by using
-    Composer's autoloader (``vendor/autoload.php``).
+    Composer's autoloader (``vendor/autoload.php``), which is included in
+    the ``app/autoload.php`` file.
 
 ``HttpFoundation`` Component
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

contributing/code/tests.rst

@@ -19,7 +19,8 @@ Dependencies (optional)
 
 To run the entire test suite, including tests that depend on external
 dependencies, Symfony2 needs to be able to autoload them. By default, they are
-autoloaded from `vendor/` under the main root directory.
+autoloaded from `vendor/` under the main root directory (see
+`autoload.php.dist`).
 
 The test suite needs the following third-party libraries: