net: move interface removal notification up in if_detach_internal

This is needed to prevent having interfaces with ifp->if_addr == NULL
on bridge interfaces. Moving the notification event handlers up makes
sure the interfaces are removed before doing any more cleanup.

Sponsored by: Citrix Systems R&D
Reviewed by: melifaro
Differential Revision: https://reviews.freebsd.org/D598

net/if.c
 - Move interface removal notification up in if_detach_internal.
print additional debugging info in virtqueue_dump()
(not fundamental, but useful to debug performance issues on vtnet)

MFC after:	3 days
Use mount protocol version 3 by default for showmount and umount.
mount_nfs effectively uses mount protocol v3 by default already.
v1 mount protocol is being removed along with nfsv2 by a high profile NFS
appliance vendor and our legacy v1 mount protocol usage causes rpc errors.
Update to the current version of netmap.
Mostly bugfixes or features developed in the past 6 months,
so this is a 10.1 candidate.

Basically no user API changes (some bugfixes in sys/net/netmap_user.h).

In detail:

1. netmap support for virtio-net, including in netmap mode.
  Under bhyve and with a netmap backend [2] we reach over 1Mpps
  with standard APIs (e.g. libpcap), and 5-8 Mpps in netmap mode.

2. (kernel) add support for multiple memory allocators, so we can
  better partition physical and virtual interfaces giving access
  to separate users. The most visible effect is one additional
  argument to the various kernel functions to compute buffer
  addresses. All netmap-supported drivers are affected, but changes
  are mechanical and trivial

3. (kernel) simplify the prototype for *txsync() and *rxsync()
  driver methods. All netmap drivers affected, changes mostly mechanical.

4. add support for netmap-monitor ports. Think of it as a mirroring
  port on a physical switch: a netmap monitor port replicates traffic
  present on the main port. Restrictions apply. Drive carefully.

5. if_lem.c: support for various paravirtualization features,
  experimental and disabled by default.
  Most of these are described in our ANCS'13 paper [1].
  Paravirtualized support in netmap mode is new, and beats the
  numbers in the paper by a large factor (under qemu-kvm,
  we measured gues-host throughput up to 10-12 Mpps).

A lot of refactoring and additional documentation in the files
in sys/dev/netmap, but apart from #2 and #3 above, almost nothing
of this stuff is visible to other kernel parts.

Example programs in tools/tools/netmap have been updated with bugfixes
and to support more of the existing features.

This is meant to go into 10.1 so we plan an MFC before the Aug.22 deadline.

A lot of this code has been contributed by my colleagues at UNIPI,
including Giuseppe Lettieri, Vincenzo Maffione, Stefano Garzarella.

MFC after:	3 days.
Add support for reading i2c SFP/SFP+ data from NIC driver and
presenting most interesting fields via ifconfig -v.
This version supports Intel ixgbe driver only.

Tested on:	Cisco,Intel,Mellanox,ModuleTech,Molex transceivers
MFC after:	2 weeks
Move the imx6 sysctl temperature info to hw.imx6 where all the other
soc-wide info lives.  It was under dev.imx6_anatop.0.

What does anatop mean anyway?  Nobody seems to know, so it's probably
not where somebody will think to look for imx6 hardware info.
Factor out the common code for function boundary tracing instead of
duplicating the entire implementation for both x86 and powerpc. This makes
it easier to add support for other architectures and has no functional
impact.

Phabric:	D613
Reviewed by:	gnn, jhibbits, rpaulo
Tested by:	jhibbits (powerpc)
MFC after:	2 weeks
* Use standard net/sff8472.h header for sff bits and offsets.
* Convert sff_8472_id to 'const char *' to please clang.

Pointed by:	np
Clean up unused definitions.
Rename the old initarm_* functions to the new platform_* names.  Also
move the registration of the static device map table into the function
intended to do devmap init stuff.
When the initarm_* routines were renamed to platform_* and moved to their
own header file, the lovely block of comments explaining what the generic
init code expects of the soc implementations got lost, restore it.
Add missing DPADD to Makefile.

PR:	192733
Bring in the new automounter, similar to what's provided in most other
UNIX systems, eg. MacOS X and Solaris.  It uses Sun-compatible map format,
has proper kernel support, and LDAP integration.

There are still a few outstanding problems; they will be fixed shortly.

Reviewed by:	allanjude@, emaste@, kib@, wblock@ (earlier versions)
Phabric:	D523
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
Merge remote-tracking branch 'upstream/master'

Conflicts:
	etc/autofs/special_hosts
	etc/autofs/special_null
	etc/rc.d/automount
	etc/rc.d/automountd
	etc/rc.d/autounmountd
	usr.sbin/autofs/popen.c