Add Dropbox catalog

Fix Google Music streaming

modules/Dropbox/autoload.php

@@ -0,0 +1,31 @@
+<?php
+namespace Dropbox;
+
+// The Dropbox SDK autoloader.  You probably shouldn't be using this.  Instead,
+// use a global autoloader, like the Composer autoloader.
+//
+// But if you really don't want to use a global autoloader, do this:
+//
+//     require_once "<path-to-here>/Dropbox/autoload.php"
+
+/**
+ * @internal
+ */
+function autoload($name)
+{
+    // If the name doesn't start with "Dropbox\", then its not once of our classes.
+    if (\substr_compare($name, "Dropbox\\", 0, 8) !== 0) return;
+
+    // Take the "Dropbox\" prefix off.
+    $stem = \substr($name, 8);
+
+    // Convert "\" and "_" to path separators.
+    $pathified_stem = \str_replace(array("\\", "_"), '/', $stem);
+
+    $path = __DIR__ . "/" . $pathified_stem . ".php";
+    if (\is_file($path)) {
+        require_once $path;
+    }
+}
+
+\spl_autoload_register('Dropbox\autoload');