Introduced common exception superclass

CloudObjects/SDK/Exceptions/SDKException.php

@@ -0,0 +1,15 @@
+<?php
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+ 
+namespace CloudObjects\SDK\Exceptions;
+
+/**
+ * The common superclass for all Exceptions thrown by the SDK.
+ * It is also thrown directly for errors that have no more specific Exception.
+ */
+class SDKException extends \Exception {
+
+}