Convert the lockstat(1) man page to mdoc and make sure that it gets
installed. Additionally, remove Solaris-specific sections and references,
and replace example outputs with output from lockstat on FreeBSD, since
lockstat's output contains stack traces.

This change also removes some examples that don't seem to work properly on
FreeBSD. The examples should be re-added when lockstat is fixed.

Reported by:	avg
MFC after:	1 week
If the initial attempt to open /dev/ksyms fails, kldload the ksyms module
and retry.
When reentering kdb, typically due to a bug causing trap or assert in
the code executed in the context of debugger, do not be ashamed to
inform loudly about the re-entry.  Also, print the backtrace before
obliterating current stack with longjmp, allowing the operator to see
a place which caused the bug.

The change should make it less mysterious debugging the ddb itself.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Move new pf includes to the pf directory. The pfvar.h remain
in net, to avoid compatibility breakage for no sake.

The future plan is to split most of non-kernel parts of
pfvar.h into pf.h, and then make pfvar.h a kernel only
include breaking compatibility.

Discussed with:		bz
Several small fixes for the amd64 minidump code.

In report_progress(), use nitems(progress_track) instead of manually
hard-coding array size.  Wrap long line.

In blk_write(), code verifies that ptr and pa cannot be non-zero
simultaneously.  The later check for the page-alignment of the ptr
argument never triggers due to pa != 0 always implying ptr == NULL.  I
believe that the intent was to ensure that physicall address passed is
page-aligned, since the address is (temporary) mapped for the duration
of the page write.

Clear the progress_track.visited fields when starting minidump.  If
minidump is restarted or taken second time during the system lifetime,
progress is not printed otherwise, making operator suspectible to the
dump status.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Remove the last dregs of trapframe_t.  It turns out only arm was using
this type, so remove it to make arm code more consistant with other
platforms.  Thanks to bde@ for pointing out only arm used trapframe_t.
Include lock.h before mutex.h.
Almost all if_clone consumers do not care about if_clone_event.
Do not force them to include sys/eventhandler.h. Those who
utilize EVENTHANDLER(9), will see the declaration.
Provide forward declaration for struct ifnet. Consumers
of this header don't need contents of struct.
Fix typo.

MFC after:	3 days
Clean up the debug printing in libproc a bit. In particular:

* Don't print any error messages to stderr unless DEBUG is defined.
* Add a DPRINTFX macro for use when errno isn't set.
* Print the error string from libelf when appropriate.
Import pf.c 1.635 and pf_lb.c 1.4 from OpenBSD

Stricter state checking for ICMP and ICMPv6 packets: include the ICMP type

in one port of the state key, using the type to determine which
side should be the id, and which should be the type. Also:
- Handle ICMP6 messages which are typically sent to multicast
  addresses but recieve unicast replies, by doing fallthrough lookups
  against the correct multicast address.  - Clear up some mistaken
  assumptions in the PF code:
- Not all ICMP packets have an icmp_id, so simulate
  one based on other data if we can, otherwise set it to 0.
  - Don't modify the icmp id field in NAT unless it's echo
  - Use the full range of possible id's when NATing icmp6 echoy

Difference with OpenBSD version:
- C99ify the new code
- WITHOUT_INET6 safe

Reviewed by:	glebius
Obtained from:	OpenBSD
Improt pf.c 1.636 from OpenBSD

Original log:
Make sure pd2 has a pointer to the icmp header in the payload; fixes
panic seen with some some icmp types in icmp error message payloads.

Obtained from:	OpenBSD
Import pf.c 1.638 from OpenBSD

Original log:
Some ICMP types that also have icmp_id, pointed out by markus@

Obtained from:	OpenBSD
edquota: Don't pass fd for temporary file to editor.

The editor opens the temporary file by name.
Import pf_print_state.c 1.54 from OpenBSD

Original log:
pfctl -ss printed state levels for ICMPv6. Disable this the same
way it has already been done for ICMPv4.

Difference with OpenBSD:
- WITHOUT_INET6 safe

Obtained from:	OpenBSD
Add bus_dmamap_load_ma() function to load map with the array of
vm_pages.  Provide trivial implementation which forwards the load to
_bus_dmamap_load_phys() page by page.  Right now all architectures use
bus_dmamap_load_ma_triv().

Tested by:	pho (as part of the functional patch)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Add a virtual table for the busdma methods on x86, to allow different
busdma implementations to coexist.  Copy busdma_machdep.c to
busdma_bounce.c, which is still a single implementation of the busdma
interface on x86 for now.  The busdma_machdep.c only contains common
and dispatch code.

Tested by:	pho (as part of the larger patch)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 month
Make sure the PCB is aligned on 8 bytes, we may use ldrd/strd to access it,
which may have strong alignment requirements.
Use the size of the MACHINE_ARCH string instead of sizeof(uint32_t). It can
happen sizeof(MACHINE_ARCH) is more than 4 bytes, and bad things would
happen. This should make the ctors being called again on armeb.