make depend

[Mike Kupfer]

The -M option apparently got added to Berkeley cpp some time after the
4.2 tapes started out the door.  (No, I don't know if it's at Harvard
because they got it from Berkeley, or whether they did it themselves.)
By the way, "cc" was changed at the same time to understand -M, so that
"make depend" lines can read

	cc -M ${INCPATH} ${SRCS} | \
	...

thus eliminating the need for shell scripts calling cpp.
-- 
Mike Kupfer
kupfer at Berkeley
...!ucbvax!kupfer
"weil, do haess Ahnung vun dae Technik, vun der ich nix verstonn."