Defines String::ucompose(fmt, arg...) for easy, i18n-friendly
composition of strings with Gtkmm >= 1.3.* (see www.gtkmm.org).
Uses Glib::ustring instead of std::string which doesn't work with
Gtkmm due to character encoding troubles with stringstreams.

Version 1.0.4.

Copyright (c) 2002, 03, 04 Ole Laursen <olau@hardworking.dk>.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License
as published by the Free Software Foundation; either version 2.1 of
the License, or (at your option) any later version.

       
Basic usage is like:
String::ucompose("This is a %1x%2 matrix.", rows, cols);

See http://www.cs.auc.dk/~olau/compose for more details.