Vim 8.1 release

Update version number and information.  Fix a couple of tests.
diff --git a/runtime/doc/pi_paren.txt b/runtime/doc/pi_paren.txt
index 1726ae6..d4ab4a0 100644
--- a/runtime/doc/pi_paren.txt
+++ b/runtime/doc/pi_paren.txt
@@ -1,4 +1,4 @@
-*pi_paren.txt*  For Vim version 8.0.  Last change: 2013 May 08
+*pi_paren.txt*  For Vim version 8.1.  Last change: 2013 May 08
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar