* dbus/dbus-message-util.c (_dbus_message_test): fix signedness warning

	* glib/dbus-glib-tool.c (main): fix warning

	* glib/dbus-binding-tool-glib.c (generate_glue): fix warning

	* dbus/dbus-connection.c (dbus_connection_read_write_dispatch):
	add a new function that can be used in simple applications that
	don't have a main loop and are willing to block