Some cleanup of the robot vision system:

	* Makeconf.in: Add INSTALL_INCDIR for includes, EVENTSYS for
	whether or not the event system is available, HAVE_MEZZANINE for
	whether or not we'll be building mezzanine, and GTK_CONFIG which
	refers to the gtk-config binary, if there is one.

	* config.h.in: Add HAVE_LINUX_VIDEODEV_H and HAVE_MEZZANINE
	defines.

	* configure, configure.in: Check for the robot vision system
	dependencies.  Add mezzanine template files.

	* robots/GNUmakefile.in: Add some conditionals for directories
	that depend on the event-system and mezzanine.

	* robots/mezzanine/GNUmakefile.in,
	robots/mezzanine/libfg/GNUmakefile.in,
	robots/mezzanine/libmezz/GNUmakefile.in,
	robots/mezzanine/mezzanine/GNUmakefile.in,
	robots/mezzanine/mezzcal/GNUmakefile.in,
	robots/mezzanine/rtk2/GNUmakefile.in: Fold mezzanine into the
	testbed's build system.

	* robots/vmcd/GNUmakefile.in: When building the vmc-client, use
	the mezzanine that we build locally instead of an installed
	version.

	* robots/vmcd/test_vmc-client.sh.in, robots/vmcd/test_vmcd.sh.in,
	robots/vmcd/test_vmcd2.sh, robots/vmcd/test_vmcd3.sh,
	robots/vmcd/test_vmcd4.sh: Bring the test cases up-to-date with
	respect to the actual code.

	* robots/vmcd/vmc-client.c: A bunch of cleanups and bug fixes: add
	comments, set TCP_NODELAY on the client sockets (doh), etc...