ZP-890 Bump version to 2.3.0alpha2.

Released under the Affero GNU General Public License (AGPL) version 3.

src/version.php

@@ -6,7 +6,7 @@
 *
 * Created   :   18.04.2008
 *
-* Copyright 2007 - 2013, 2015 Zarafa Deutschland GmbH
+* Copyright 2007 - 2016 Zarafa Deutschland GmbH
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
@@ -41,4 +41,4 @@
 * Consult LICENSE file for details
 ************************************************/
 
-define("ZPUSH_VERSION", "2.3.0alpha1");
+define("ZPUSH_VERSION", "2.3.0alpha2");