'RELENG_4_2_0_RELEASE'.

This commit was manufactured to restore the state of the 4.2-RELEASE image.
Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

  - Check FTP_PASSIVE_MODE for the value "NO" (implying active mode)
    instead of just checking whether it is defined
  - Remove bogus "PASV toggle" behavior from ftpPassive()
  - Clarify the relationship between FTP_PASSIVE_MODE and ftpPassive()
    in the man page

Don't assume 227 and 228 replies enclose remote address with parentheses.
(rev 1.36 -> 1.37)

of the typeset output, tend to make diffs harder to read and provide
bad examples for new-comers to mdoc.

Reviewed by:	marcel, and make world

Submitted by: bde

-----------------------------

Most of the userland changes are in libc. For both the alpha
and the i386 setjmp has been changed to accomodate for the
new sigset_t. Internally, libc is mostly rewritten to use the
new syscalls. The exception is in compat-43/sigcompat.c

The POSIX thread library has also been rewritten to use the
new sigset_t. Except, that it currently only handles NSIG
signals instead of the maximum _SIG_MAXSIG. This should not
be a problem because current applications don't use any
signals higher than NSIG.

There are version bumps for the following libraries:
  libdialog
  libreadline
  libc
  libc_r
  libedit
  libftpio
  libss

These libraries either a) have one of the modified structures
visible in the interface, or b) use sigset_t internally and
may cause breakage if new binaries are used against libraries
that don't have the sigset_t change. This not an immediate
issue, but will be as soon as applications start using the
new range to its fullest.

NOTE: libncurses already had an version bump and has not been
      given one now.

NOTE: doscmd is a real casualty and has been disconnected for
      the moment. Reconnection will eventually happen after
      doscmd has been fixed. I'm aware that being the last one
      to touch it, I'm automaticly promoted to being maintainer.
      According to good taste this means that I will receive a
      badge which either will be glued or mechanically stapled,
      drilled or otherwise violently forced onto me :-)

NOTE: pcvt/vttest cannot be compiled with -traditional. The
      change cause sys/types to be included along the way which
      contains the const and volatile modifiers. I don't consider
      this a solution, but more a workaround.

initialization of sa_flags added so that the 'struct sigaction'
can be declared local in both functions that use the global
(static) declaration. Remove the global declaration.

PR:		docs/13702
Submitted by:	Stephen J. Roznowski <sjr@home.com>
Reviewed by:	mpp