Unite help output for tools

Unite help output for tools

	* tools/biar.cc (std::ostream): Add a using directive.
	(display_usage): Make it take a string reference and an ostream
	as parameters. Use the ostream argument as an output stream
	instead of a hard-coded cout.
	Prettify output.
	(main): Call display_usage with new parameters.
	* tools/bidiff.cc (display_usage): Declare it static.
	Prettify output.
	* tools/bidw.cc (display_usage): Prettify output.
	* tools/bilint.cc (display_usage): Declare it static.
	Prettify output.
	* tools/bisym.cc (std::cerr): Add a using directive.
	(prog_name): Rename progname into this.
	(display_usage): Rename show_help into this.
	Add an ostream as a parameter. Use the ostream argument
	as output stream insted of a hard-coded cout.

Signed-off-by: Ondrej Oprala <ooprala@redhat.com>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>