Add Exception if MB support is not available in PHP

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@3813 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

fts.php

@@ -51,6 +51,15 @@ class fts
     return $this->regexes;
   }
 
+  /** The constructor check the availability of the MB module
+    */
+  public function __construct ()
+  {
+    if (! function_exists ("mb_strlen"))
+      throw new \Exception ("PHP don't have the MB Support. Please add it !",
+        500);
+  }
+
   /** Search the text provided in $query in the database
     * @param string $query The text to found in the database
     * @return array The operator and the associated regex value to search