Merge branch 'topic/manual.10'

Merge branch 'topic/manual.10'

* topic/manual.10:
  nail.1: reference RFC 6752 in FAQ ("hangs on startup")
  *features* and `features' are "the same"
  Not "binary", but "boolean" variables! (Predrag Punosevac)..
  nail.1: more on no*dot* / *ignoreeof*
  nail.1: more on sortability (Rudolf Sykora)..
  nail.1: use .Ux, better HISTORY
  nail.1, COPYING: remove Open Group reference (no text included?)
  nail.1:  tweak! tweak! tweak!  ..the drunken sailor!
  nail.1: tweak (?) -d/-v / *debug*/*verbose*
  nail.1, make.rc: make clear we use extended regular expressions
  nail.1: fix typo (Hariskar (archlinux Wiki))
  nail.1,nail.rc: (improve) document(ation of) .rc content format
  nail.1: rework "On URL syntax and credential lookup"
  nail.1: mention "portable character set", e.g., for `urlencode'
  nail.1: what is an environment variable (Michael Convey)
  nail.1: try improve states / MBOX etc. relation (Michael Convey)
  nail.1: talk about address lists (again) (Michael Convey)..
  nail.1: we support searching, really (Predrag Punosevac)
  nail.1: ooops, the `if' T/t condition is _not_ POSIX!
  nail.1: crossref+tweak *headline*/%d, *datefield{,markout-older}*
  nail.1: some tweaks here and there
  nail.h, nail.1: sort ALL options alphabetically!..
  nail.1: drop 4th BSD license clause
  Drop the temporary second occurrance of *s-n-d-a* again