Update runtime files.  Add Rust support.
diff --git a/runtime/doc/helphelp.txt b/runtime/doc/helphelp.txt
index 20f1ed8..80fc70c 100644
--- a/runtime/doc/helphelp.txt
+++ b/runtime/doc/helphelp.txt
@@ -1,4 +1,4 @@
-*helphelp.txt*	For Vim version 8.0.  Last change: 2017 Feb 09
+*helphelp.txt*	For Vim version 8.0.  Last change: 2017 Mar 19
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -142,7 +142,8 @@
 			already opened, then the location list for that window
 			is used.  Otherwise, a new help window is opened and
 			the location list for that window is set.  The
-			location list for the current window is not changed.
+			location list for the current window is not changed
+			then.
 
 							*:exu* *:exusage*
 :exu[sage]		Show help on Ex commands.  Added to simulate the Nvi