move all exception declaration to their own file

mobile.webservice.php

@@ -1,26 +1,5 @@
 <?php
 
-class WebException extends Exception
-{
-    private $excname;
-
-    /**
-     * @param string $name
-     * @param string $reason
-     * @param int $code
-     */
-    function __construct($name, $reason, $code)
-    {
-        $this->excname = $name;
-        parent::__construct($reason, $code);
-    }
-
-    public function getName()
-    {
-        return $this->excname;
-    }
-}
-
 abstract class WebService
 {
     private $func = null;