Bind examples/calc++ to the package.

* examples/calc++/Makefile: Remove, replaced by...
* examples/calc++/Makefile.am: ... this new file.
* examples/calc++/test: Remove input.
* examples/calc++/compile: Remove.
* examples/Makefile.am: New.
* configure.ac, Makefile.am: Adjust.
* doc/Makefile.am (clean-local): New, for more recent texi2dvis.

configure.ac

@@ -129,5 +129,7 @@ AC_CONFIG_FILES([Makefile
                  config/Makefile
                  po/Makefile.in
                  data/Makefile
+		 examples/Makefile
+		    examples/calc++/Makefile
                  lib/Makefile src/Makefile doc/Makefile])
 AC_OUTPUT