Merge branch 'master' into release-2.x

* master:
  Put the autoloader to work.
  Add an autoloader that allows using the old class names even after migrating to PSR-2. This makes it easier for projects using the library to migrate, as it can then be done incrementally.

composer.json

@@ -28,7 +28,8 @@
     "autoload": {
         "psr-0": {
             "SAML2\\": "src/"
-        }
+        },
+        "files": ["src/_autoload.php"]
     },
     "autoload-dev": {
         "psr-0": {

src/_autoload.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * Temporary autoloader to ensure compatibility with old, non-PSR-2 compliant classes.
+ *
+ * @author Jaime Pérez Crespo <jaime.perez@uninett.no>
+ * @package SimpleSAMLphp
+ */
+
+/**
+ * Autoload function that looks for classes migrated to PSR-2.
+ *
+ * @param string $className Name of the class.
+ */
+function SAML2_autoload($className)
+{
+    // handle classes that have been renamed
+    $renamed = array(
+        'SAML2_Const' => 'SAML2_Constants',
+    );
+    $oldName = $className;
+    if (array_key_exists($className, $renamed)) {
+        $className = $renamed[$className];
+    }
+
+    $file = dirname(__FILE__).'/'.str_replace('_', '/', $className).'.php';
+    if (file_exists($file)) {
+        require_once($file);
+        $newName = '\\'.str_replace('_', '\\', $className);
+        class_alias($newName, $oldName);
+    }
+
+}
+
+spl_autoload_register('SAML2_autoload');