🚀 go-pugleaf

The V7 kill program will not take -1 as a processid.  The kill system
call likes it just fine (it sends the signal to all processes except
0 and 1) but kill(1) thinks it is syntactically invalid.  The fix for
this is to change the line:

		if (**argv<'0' || **argv>'9')

to something like:

		if (!isdigit(**argv) && **argv != '-')

(NB if you use isdigit rather than the explicit 0 and 9, you'll need
to #include <ctype.h>.)