Add gettext and sources_parser_unittests to .app

ebin/erlydtl.app

@@ -19,7 +19,9 @@
              i18n_manager,
              po_generator,
              po_scanner,
-             sources_parser
+             sources_parser,
+             gettext,
+             sources_parser_unittests
             ]},
   {applications, [kernel, stdlib]},
   {registered, []}