Sprinke some capsicum(4) on top of bsdgrep(1).
Unfortunately, we can't effectively enter capabilities mode as early as we should (or at all) in 2/3 cases because we lack a casper file service of any kind, so go the md5(1) route and enter capabilities mode immediately after opening the last file argument.
We do enter capability mode immediately if we're only reading stdin through no arguments, so that's at least one positive. Ideally it would all get refactored to enter capabilities mode immediately before the first instance of cap_enter().
This change does conflict with D10108, but I'll sort out the merge conflicts if/when the time arises.