updated for version 7.4.191

Problem:    Escaping a file name for shell commands can't be done without a
            function.
Solution:   Add the :S file name modifier.

runtime/doc/usr_42.txt

@@ -311,7 +311,7 @@ redefine what these items do (after the default menus are setup).
 item with a bitmap.  For example, define a new toolbar item with: >
 
 	:tmenu ToolBar.Compile  Compile the current file
-	:amenu ToolBar.Compile  :!cc % -o %:r<CR>
+	:amenu ToolBar.Compile  :!cc %:S -o %:r:S<CR>
 
 Now you need to create the icon.  For MS-Windows it must be in bitmap format,
 with the name "Compile.bmp".  For Unix XPM format is used, the file name is