Some cleanup to the vision system and make wiggle work, although it is still
a bit glitchy.  This checkin is enough to identify the robots in their
pens and move them to their initial positions.

	* robots/emc/emcd.h, robots/emc/emcd.c: When rmc connects, send
	GOTOs with the initial positions given in the config file.  If rmc
	requests a vision update and one isn't available, queue the
	request and send a reply when an update does come in.

	* robots/mtp/GNUmakefile.in, robots/mtp/listNode.h,
	robots/mtp/listNode.c: Add amiga-style linked list node functions,
	tim always needs these.

	* robots/mtp/mtp.h, robots/mtp/mtp.c: Add mtp_theta function that
	produces a sane theta value between -M_PI and M_PI.

	* robots/mtp/mtp.x: Add MTP_WIGGLE_START type which causes the
	robots to stop in their tracks waiting for a real wiggle type
	(e.g. 180 deg turn).

	* robots/rmcd/rmcd.c: Tweaks, add support for MTP_WIGGLE_START.

	* robots/vmcd/GNUmakefile.in, robots/vmcd/robotObject.h,
	robots/vmcd/robotObject.c, robots/vmcd/visionTrack.h,
	robots/vmcd/visionTrack.c, robots/vmcd.c: Cleanup and make wiggle
	work.

	* robots/vmcd/vmc-client.c: If there are no objects detected in a
	camera send an error packet instead of nothing, so vmcd can keep
	in sync with the frames.