Bug fixes in iconv(3) UTF-7 support.

- Add ' to the list of directly encoded characters and * to the list of
  optionally directly encoded characters as per RFC 2152.

- In _citrus_UTF7_mbtoutf16 on end of input when the next output character
  has only been partially decoded, save a copy of the buffer of input
  characters (not just its length).  On the next call with more input
  characters this buffer is reprocessed together with the new input to
  form a fully decoded output character.

- At the end of a base64 encoded sequence fully discard '-' (BASE64_OUT)
  by decrementing psenc->chlen and i.  This is needed to make room in
  psenc->ch (input buffer) in case the next input character starts a new
  base64 encoded sequence.  And also, if this is the end of input and no
  output character can be returned, this brings the encoder in the initial
  state as indicated by _citrus_UTF7_stdenc_get_state_desc_generic which
  is used by the caller to distinguish between no output and partial
  output.

- In _citrus_UTF7_mbrtowc_priv pass the s parameter (input pointer)
  directly to _citrus_UTF7_mbtoutf16 instead of a copy (s0).  This way s
  is updated correctly in case of errors.

- In _citrus_UTF7_mbrtowc_priv when called with psenc->surrogate set
  (previous call did not have enough input), retrieve the previously
  decoded UTF-16 character from (psenc->cache >> psenc->bits) instead of
  (psenc->cache >> 2).

MFC after:	5 days
Document the 'dvdrom' target.

MFC after:	3 days
X-MFC-With:	r258310
Sponsored by:	The FreeBSD Foundation
Also delete lib32 libiconv.

Reported by:	Tomoaki AOKI <junchoon@dec.sakura.ne.jp>
MFC after:	3 days
Remove WITHOUT_PROFILE=1 for the dvd1.iso medium.

Requested by:	hrs
MFC after:	3 days
X-MFC-With:	r258310
Sponsored by:	The FreeBSD Foundation
Simplify PKG_ABI for pkg-stage.sh.

Submitted by:	hrs
MFC after:	3 days
X-MFC-With:	r258310
Sponsored by:	The FreeBSD Foundation
gcc: Record some previous commits in the gcc43 ChangeLog.

It is useful to update the ChangeLog with upstream references
related to our local r189824 and r255095.

MFC after:	3 weeks
Indicate which options are extensions to POSIX.

Inspired by:	DragonFlyBSD
Allow ethernet drivers to pass in packets connected via the nextpkt pointer.
Handling packets in this way allows drivers to amortize work during packet reception.

Submitted by:	Vijay Singh
Sponsored by:	NetApp
Bump .Dd for recent change
Need to also test for defined(${v}_${PROG})
Import the axge(4) driver for the ASIX AX88178A and AX88179 USB Ethernet
adapters. Both devices support Gigabit Ethernet and USB 2.0, and the AX88179
supports USB 3.0. The driver was written by kevlo@ and lwhsu@, with a few
bug fixes from me.

MFC after:	2 months
Regenerate usb.conf after r258331.
Provide the correct path to bus_autoconf.sh.
Implement soft pressure on UMA cache bucket sizes.

Every time system detects low memory condition decrease bucket sizes for
each zone by one item.  As result, higher memory pressure will push to
smaller bucket sizes and so smaller per-CPU caches and so more efficient
memory use.

Before this change there was no force to oppose buckets growth as result
of practically inevitable zone lock conflicts, and after some run time
per-CPU caches could consume enough RAM to kill the system.
Add two new UMA bucket zones to store 3 and 9 items per bucket.

These new buckets make bucket size self-tuning more soft and precise.
Without them there are buckets for 1, 5, 13, 29, ... items.  While at
bigger sizes difference about 2x is fine, at smallest ones it is 5x and
2.6x respectively.  New buckets make that line look like 1, 3, 5, 9, 13,
29, reducing jumps between steps, making algorithm work softer, allocating
and freeing memory in better fitting chunks.  Otherwise there is quite a
big gap between allocating 128K and 5x128K of RAM at once.
Grow UMA zone bucket size also on lock congestion during item free.

Lock congestion is the same, whether it happens on alloc or free, so
handle it equally.  Now that we have back pressure, there is no problem
to grow buckets a bit faster.  Any way growth is much slower then in 9.x.
Implement mechanism to safely but slowly purge UMA per-CPU caches.

This is a last resort for very low memory condition in case other measures
to free memory were ineffective.  Sequentially cycle through all CPUs and
extract per-CPU cache buckets into zone cache from where they can be freed.
Reenable vfs.zfs.zio.use_uma for amd64, disabled at r209261.

On machines with seveal CPUs and enough RAM this can easily twice improve
ZFS performance or twice reduce CPU usage.  It was disabled three years
ago due to memory and KVA exhaustion reports, but our VM subsystem got
improved a lot since that time, hopefully enough to make another try.
One more BIND remnant: /etc/mtree/BIND.chroot.dist

Discussed with:	des
Support SNI in libfetch

SNI is Server Name Indentification which is a protocol for TLS that
indicates the host that is being connected to at the start of the
handshake. It allows to use Virtual Hosts on HTTPS.

Submitted by:	sbz
Submitted by:	Michael Gmelin <freebsd@grem.de> [1]
PR:		kern/183583 [1]
Reviewed by:	des
Approved by:	bapt
MFC after:	1 week