utrace-ptrace && detach with signal semantics

[Roland McGrath]

> I think always-reply-to-all is the best policy ;)

For some people's mail-handling habits it makes a difference, so it is
always safest not to trim individuals.  For me personally, I always
see the list copies just the same as the ones CC'd to me personally,
so I don't care to be in the CC list as long as the mailing list is
CC'd (and I prefer shorter CC lists for no special reason).


Thanks,
Roland