Added availabililty annotations to respond to concerns of /F.

Doc/lib/libgetpass.tex

 \section{\module{getpass}
-         --- Portable password reading.}
+         --- Portable password input}
 
 \declaremodule{standard}{getpass}
+\modulesynopsis{Portable reading of passwords and retrieval of the userid.}
 \moduleauthor{Piers Lauder}{piers@cs.su.oz.au}
-% Windows support by Guido van Rossum.
+% Windows (& Mac?) support by Guido van Rossum.
 \sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
 
-\modulesynopsis{Portable reading of passwords and retrieval of the userid.}
-
 
 The \module{getpass} module provides two functions:
 
@@ -16,11 +15,13 @@ The \module{getpass} module provides two functions:
   Prompt the user for a password without echoing.  The user is
   prompted using the string \var{prompt}, which defaults to
   \code{'Password: '}.
+  Availability: Macintosh, \UNIX{}, Windows.
 \end{funcdesc}
 
 
 \begin{funcdesc}{getuser}{}
   Return the ``login name'' of the user.
+  Availability: \UNIX{}, Windows.
 
   This function checks the environment variables \envvar{LOGNAME},
   \envvar{USER}, \envvar{LNAME} and \envvar{USERNAME}, in order, and