Vim 8.1 release

Update version number and information.  Fix a couple of tests.
diff --git a/runtime/doc/digraph.txt b/runtime/doc/digraph.txt
index a5cefc2..2a23222 100644
--- a/runtime/doc/digraph.txt
+++ b/runtime/doc/digraph.txt
@@ -1,4 +1,4 @@
-*digraph.txt*   For Vim version 8.0.  Last change: 2016 Nov 04
+*digraph.txt*   For Vim version 8.1.  Last change: 2016 Nov 04
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar