Updated runtime files.

Add Serbian translations and spell checking.
diff --git a/runtime/doc/repeat.txt b/runtime/doc/repeat.txt
index 2e9746b..e1e370c 100644
--- a/runtime/doc/repeat.txt
+++ b/runtime/doc/repeat.txt
@@ -1,4 +1,4 @@
-*repeat.txt*    For Vim version 8.0.  Last change: 2017 Dec 17
+*repeat.txt*    For Vim version 8.0.  Last change: 2018 Feb 11
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar