MFC vtfontcvt improvements:

r267011: Make height and width optional arguments

  Now defaults to a 16x8 font size.  The height and width can be specified
  using -h and -w respectively.

r267012: Make the bold font optional

r267035: Use a hash to speed up glyph deduplication

  Walking a linked list of all glyphs to look for a duplicate is very slow
  for large fonts (e.g., for CJK character sets).  In my test the runtime
  for a sample 40000 character font went from just over 80 seconds on
  average to just over 2 seconds.

r267119: -w sets the width, not height

r267123: Support "GNU Unifont" format font data

  The GNU Unifont .hex format is a text file.  Each line represents one
  glyph and consists of a four-digit hex code point, a colon, and pairs of
  hex digits representing the bitmap.  By default an 8x16 font is assumed,
  with 16x16 double-width glyphs, resulting in either 32 or 64 hex digits
  for the bitmap.

  Our version of the file format supports comments at the top of the file
  to set the height and width:

  Each row of bitmap data is rounded up to byte width - for example, a
  10-pixel wide font uses 4 characters per row.

  See http://czyborra.com/unifont/ for more background on the original
  format.

r267126: Accept space after BITMAP in .bdf parser

  The Unifont BDF generator incorrectly adds a space after BITMAP, and
  and that error has been widely propagated.

r267173: use -h height and -w width args

r267298: Hide stats by default and improve error handling

  The font stats are interesting, but rather verbose.

r267301: Speed up bold glyph map deduplication

  Perform an O(n) deduplication pass over the bold maps at the end, rather
  than walking the normal map list to look for a duplicate glyph each time
  a bold mapping entry is added.

r267324: handle failure writing output font

r267337: move to usr.bin/vtfontcvt

  vtfontcvt is useful for end users to convert arbitrary bitmap fonts
  for use by vt(4).  It can also be used as a build tool, allowing us
  to keep the source font data in the src tree rather than uuencoded
  binaries.

  Reviewed by:  ray, wblock (D183)

r267366: Avoid leaking file pointer on error

  CID:          1222506, 1222505

r268022: Rename the WITHOUT_VT_SUPPORT knob to WITHOUT_VT

  The _SUPPORT knobs have a consistent meaning which differs from the
  behaviour controlled by this knob.  As the knob is opt-out and has not
  appeared in a release the impact should be low.

r268172: correct width calculation (.hex files and commandline)

r268948: Use the standard way of printing the usage string

r268949: Remove redundant return statement after errx

Also update vtfontcvt(8), based on inclusion in FreeBSD 10.1

Sponsored by:	The FreeBSD Foundation
MFC r268601:

Make bind(2) and connect(2) return EAFNOSUPPORT for AF_UNIX on wrong
address family.

See https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=191586 for the
original discussion.

Reviewed by:	terry
MFC r268643:

Document that listen(2) can fail with EDESTADDRREQ.
MFC r268787:

Deprecate m_act.  Use m_nextpkt always.
MFC r268825:

Remove deprecated definition "m_act".

Suggested by:	adrian, glebius
MFC r268384:
When the lock was stolen from us, retry the whole lock sequence in kernel,
instead of returning EINTR.
MFC r268660:
Make amd64 pmap_copy_pages() functional for pages not mapped by DMAP.
MFC r258471: Don't abort SMAP processing after an entry of length 0

  Length 0 is not special and should just be skipped.  This is the same
  behaviour as i386.

Sponsored by:	The FreeBSD Foundation
MFC r268420:
Remove IO_SYNC flag when writing extended file attributes on ZFS.

While it is possible to create and write file, modify its permissions, etc.
without ever doing sync, it looks odd that it is required for setting
extended file attributes on ZFS.  UFS does not do sync there too.

Samba uses those extended attributes to store some its data, and doing it
synchronously by many times reduces file creation performance for systems
without SLOG device.
MFC r268947: Hide syscons-specific workaround under DEV_SC
MFC r267613 (by trasz):
Implement redirection handling in initiator.
MFC r266169 (by trasz):
Remove unused variable.
MFC r267608 (by trasz):
Use proper term in debug messages.
MFC r267609 (by trasz):
Improve code a little; no functional changes.
MFC r267612 (by trasz):
Get rid of unneccessary argument.
MFC r268289:
Fix minor copy-paste bug in r268284.
MFC r268457 (by pluknet):
Fix typos.
MFC r267213 (by alc):
Add a page size field to struct vm_page.

Approved by:	alc
MFC r268466:
Calculate the amount of resident pages by looking in the objects chain
backing the region. Add a knob to disable the residency calculation at
all.

MFC r268490:
Unconditionally initialize addr to handle the case of changed map
timestamp while the map is unlocked.

MFC r268711:
Change the calculation of the kinfo_vmentry field kve_private_resident
to reflect its name.

MFC r268712:
Followup to r268466.
- Move the code to calculate resident count into separate function.
  It reduces the indent level and makes the operation of
  vmmap_skip_res_cnt tunable more clear.
- Optimize the calculation of the resident page count for map entry.
  Skip directly to the next lowest available index and page among the
  whole shadow chain.
- Restore the use of pmap_incore(9), only to verify that current
  mapping is indeed superpage.
- Note the issue with the invalid pages.
MFC r268957:

Run mtree for BSD.tests.dist during make xdev-install, if the tests are
enabled (which they are in the default configuration).  Otherwise, it
will fail because ${XDDESTDIR}/usr/include/atf-c does not exist.