Major rewrite of how ld is configured. The major idea

	Major rewrite of how ld is configured.  The major idea
	is to use shell scripts to generate everything.
	* Each emulation is defined by a short shell script with
	extension *.sh that specifies the emulation-specific
	parameters (such as the name of the *.sh-sc and *.em
	files to use).
	* genscript.sh is the master shell script used to generate
	an emulation.  It is passed various argument, including
	the name a the emulation-speciic *.sh file that it
	"sources" to set variables to emulation-specifc parameters.