applied a patch from Norm Jacobs to allow "printcap name = lpstat"

applied a patch from Norm Jacobs to allow "printcap name = lpstat"
to use lpstat to obtain the printer list on systemV systems.

I've now made this the default on all SYSV systems.

Jeremy, you were a little worried about the security of this patch. I
believe it's OK as the user has no control over the options given to
popen() and the pipe is only open for reading.
(This used to be commit 6a83de0ae954bb18d3f15382f2b0b3259fedff09)