Even more robot-related cleanup:

	* robots/primotion/Makefile: Add an install target that copies the
	executables to the robots.  The default set of robots is
	"garcia1-6", if you want a subset do: 'make install
	ROBOTS="garcia2"'

	* robots/primotion/gorobot.cc: Refactoring, add some more
	debugging output, and print the battery level at startup and every
	five minutes.