Update version number for next release.

webcomic.php

@@ -4,7 +4,7 @@
 Plugin Name: Webcomic
 Plugin URI: http://webcomic.nu
 Description: Comic publishing power for the web.
-Version: 4.0.3
+Version: 4.0.4
 Author: Michael Sisk
 Author URI: http://mgsisk.com
 License: GPL2
@@ -34,7 +34,7 @@
  * @package Webcomic
  * @copyright 2008 - 2013 Michael Sisk
  * @license //gnu.org/licenses/gpl-2.0.html GPL2
- * @version 4.0.3
+ * @version 4.0.4
  * @link http://webcomic.nu
  */
 
@@ -46,7 +46,7 @@ class Webcomic {
 	/** Internal version number.
 	 * @var string
 	 */
-	protected static $version = '4.0.3';
+	protected static $version = '4.0.4';
 
 	/** Absolute path to the Webcomic directory.
 	 * @var string