Make use of the stargate's onboard watchdog timer.

	* mote/sgtools/GNUmakefile.in: Standard makefile for sgtools.  Run
	configure as described in doc/cross-compiling.txt to make it
	compile for the stargate.

	* mote/sgtools/wagthedog.C: Enable and feed the stargate's onboard
	watchdog timer.

	* robots/primotion/pilot-wrapper.sh: Rewrite in perl.

	* tmcd/common/watchdog: Change the path of the battery log file.

	* tmcd/linux-sg/rc.stargate: Start the stargate watchdog tool and
	run the pilot-wrapper script instead of pilot directly.