Vim 8.1 release

Update version number and information.  Fix a couple of tests.
diff --git a/runtime/doc/pi_gzip.txt b/runtime/doc/pi_gzip.txt
index d8f63ac..21b6520 100644
--- a/runtime/doc/pi_gzip.txt
+++ b/runtime/doc/pi_gzip.txt
@@ -1,4 +1,4 @@
-*pi_gzip.txt*   For Vim version 8.0.  Last change: 2016 Nov 06
+*pi_gzip.txt*   For Vim version 8.1.  Last change: 2016 Nov 06
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar