Copyright (c) 1993 Xerox Corporation.  All rights reserved.
This instance of PPCR is intended for removing the spawn code in favor of creating 
and using an exec server.
Step 1:
	remove all the spawn support from the glue: done 8/30/93
		that was easy: just deleted the *Spawn*.{c,h} files from the th component
		and all related stuff from io, sig, and vd. Fixed the th/ Makefile and rebuilt.
		Still need to deal with the tst/ and xr/ components which were Spawn clients,
		but that can wait until the Exec component is ready to replace Spawn.
Step 2:
	create an exec component
	create an exec interface 
	create an exec stub implementation
	create an exec server implementation: optionally
		fork the exec server during world initialization
	create an exec client implementation

-- Carl Hauser 8/30/93