Kernel: Set max io size limit for all disk devices

* Prior to this change, slice and partition devices did not inherit their
  parent maximum IO size limit

* IO transactions on these devices could thus never be bigger than the
  old 64KB DFLTPHYS defaul kernel limit
Sync zoneinfo database with tzdata2012c from munnari.oz.au

africa:         8.33 -> 8.35
asia:           8.70 -> 8.73
northamerica:   8.53 -> 8.54

* africa: Morocco 2012 DST from last Sunday in April through last
    Sunday in September.

* asia: Change start of DST in Syria to last Friday in March in
    2012 and (as a guess) forward. Starts and (guessed) ends of
    DST in West Bank and Gaza for 2012. Also add a missing HTML
    directive at the top of the file.

* northamerica: Start and end of DST in Haiti in 2012 according
    to US rules.
Merge branch 'master' into gsocdrm_jfree
kernel -- FFS: Take softdep lock in softdep_disk_io_initiation.

softdep_disk_io_initiation was using the mplock rather than the softdep
lock to protect the softdep work queue and items on it. Take the softdep
lock and allow it to be taken recursively, so that io_start bioops can
call into other parts of softdep. Prevents softdep completion callback
from racing softdep_disk_io_initiation, remaining panics of 2291.

Eventually the MPLOCK in the bio_ops callback can go away, but that will
require more testing.

Closes-bug: 2291
kernel - Reduce impact of write_behind on small/temporary files

* Do not start issuing write-behind writes until a file has grown past
  a certain size, otherwise we wind up issuing excessive I/O for
  small files and for temporary files which might be quickly deleted.

* Add vfs.write_behind_minfilesize sysctl (defaults to 10MB).
kernel - Add max I/O size cap to vmaxiosize()

* Cap the returned value at MAXPHYS, allowing VCHR devices to set a
  higher max-IO limit (according to DMA limitations) without blowing
  out the pbuf's that the frontend uses to build clustered I/O.
vkernel: cap vdisk max. io size to MAXPHYS
Merge branch 'master' into gsocdrm_merger
kernel -- vnlru: Remove MPLOCK from vnlru.

vnlru didn't need the mplock through its main loop.
carp: Make sure that carp_ifaddr only happens in netisr0
carp: Remove unused code
pf/carp: Our carp is never layed out in the fashion used by pf

Comment out the invalid usage temporarily
carp: Lockless MPSAFE step 1 of many

Dispatch ifnet_detach_event to netisr0 for further processing
carp: Lockless MPSAFE step 2 of many

Dispatch major part of clone_destroy to netisr0 for further processing
carp: Lockless MPSAFE step 3 of many

Dispatch main part of if_init to netisr0 for further processing
carp: Lockless MPSAFE step 4 of many

Dispatch "stop" method from if_ioctl to netisr0 for further processing
carp: Lockless MPSAFE step 5 of many

Dispatch SIOCSVH to netisr0 for further processing
carp: Lockless MPSAFE step 6 of many

Run the carp information retrieving code in netisr0
kernel/acpi: Remove the redefinition of kthread_create().

It's a relict from an old pile of #ifdefs that defined various
incarnations of kthread_create()s for various FreeBSD versions.
The #ifdefs have since been removed and this #define is what
used to be the __DragonFly__ case.

There are only 3 places where kthread_create() is used in ACPI,
so remove it because it's just confusing.

While here, fix a non-constant format string in one of the
kthread_create()s.
bktr(4): Let kthread_create() construct the thread name.