\file is not allowed in section titles -- converting to PDF fails due to

weird macro-expansion issues.  A better solution may be available in the
future, but this will do for now.

Add an index entry.  More should probably be added as well.

Doc/lib/libgettext.tex

@@ -240,7 +240,7 @@ returns a Unicode string by passing both the translated message string
 and the value of the ``protected'' \member{_charset} variable to the
 builtin \function{unicode()} function.
 
-\subsubsection{Solaris \file{.mo} file support}
+\subsubsection{Solaris message catalog support}
 
 The Solaris operating system defines its own binary
 \file{.mo} file format, but since no documentation can be found on
@@ -248,8 +248,8 @@ this format, it is not supported at this time.
 
 \subsubsection{The Catalog constructor}
 
-GNOME uses a version of the \module{gettext} module by James
-Henstridge, but this version has a slightly different API.  Its
+GNOME\index{GNOME} uses a version of the \module{gettext} module by
+James Henstridge, but this version has a slightly different API.  Its
 documented usage was:
 
 \begin{verbatim}