Massive refactor of the analyzer branch and sync it back up with the

cloud storage branch (for the last time)

* Backported all the bugfixes from cc-5709-airtime-analyzer-cloud-storage
* Backported missing FileStorageBackend.php
* Fixed CC-6001: Track titles and artist names with slashes break audio preview
* Refactored all the MediaController code, pulling out the logic into MediaService
* Fixed an API key leak to guests in the Media API
* Made this branch work without cloud_storage.conf (defaults to file storage)
* Made ApiController's getMediaAction use the MediaService code

airtime_mvc/application/cloud_storage/StorageBackend.php

@@ -52,4 +52,14 @@ abstract class StorageBackend
     {
         $this->secretKey = $secretKey;
     }
+
+    public function deleteAllCloudFileObjects()
+    {
+        return false;
+    }
+
+    public function getFilePrefix()
+    {
+        return "";
+    }
 }