lockfile : better error message to found the class which generate the error

git-svn-id: https://svn.fournier38.fr/svn/ProgSVN/trunk@2230 bf3deb0d-5f1a-0410-827f-c0cc1f45334c

lockfile.php

@@ -18,7 +18,8 @@ class lockfile
     if (!is_dir (dirname ($this->storagelock)))
       @mkdir (dirname ($this->storagelock));
     if (!is_dir (dirname ($this->storagelock)))
-      throw new Exception ("Can't create '".dirname ($this->storagelock)."'",
+      throw new Exception ("Can't create '".dirname ($this->storagelock).
+                           "' directory for lockfile",
                            500);
     $lockid = uniqid() . '_' . md5 (mt_rand());
     $startTime = microtime (TRUE);