timeout(1): Add -v/--verbose option to show diagnosis info

[gbe]

Summary

The -v/--verbose option enables this utility to show diagnosis info to
stderr about any signal sent on timeout.

This implementation refers to GNU coreutils's timeout(1).

Obtained from: DragonFlyBSD
MFC after: 1 week

Test Plan

make in the timeout(1) directory and manual tests

[ziaee]

Manpage looks awesome. stderr(4) could also be used with Xr.

[pstef]

bin/timeout/timeout.1

37

-kill-after was replaced with -verbose?

[gbe]

bin/timeout/timeout.1

37

No, if you look at the first line the option is double listed. This was a mistake I made in the previous revision, but I corrected it first in this one.