Really disconnect pkg_install from the build.

Reported by:	Mikhail Timofeyev
Move the old iSCSI initiator source to a more appropriate place
(sys/dev/iscsi_initiator/ instead of sys/dev/iscsi/initiator/), to make
room for the new one.  This is also more logical location (kernel module
being named iscsi_initiator.ko, for example).  There is no ongoing work
on this I know of, so it shouldn't make life harder for anyone.

There are no functional changes, apart from "svn mv" and adjusting paths.
Minor mdoc nit.
Remove EOL whitespace.
Remove EOL whitespace.
Vendor import of NetBSD's libexecinfo at 2013-08-22
Tag libexecinfo 2013-08-22
MFi386:		r254619

Reimplement atomic_load_acq_64() and atomic_store_rel_64() for i386.

Noticed by:	tinderbox
Use the generation count of the pv list to work around LOR between
pmap lock and pv list lock, and use the shared locking on
pvh_global_lock in pmap_remove_write(), same as it was done for
pmap_ts_referenced().

Noted and reviewed by:	alc (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Revert r254501.  Instead, reuse the type stability of the struct pmap
which is the part of struct vmspace, allocated from UMA_ZONE_NOFREE
zone.  Initialize the pmap lock in the vmspace zone init function, and
remove pmap lock initialization and destruction from pmap_pinit() and
pmap_release().

Suggested and reviewed by:	alc (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Both cluster_rbuild() and cluster_wbuild() sometimes set the pages
shared busy without first draining the hard busy state.  Previously it
went unnoticed since VPO_BUSY and m->busy fields were distinct, and
vm_page_io_start() did not verified that the passed page has VPO_BUSY
flag cleared, but such page state is wrong.  New implementation is
more strict and catched this case.

Drain the busy state as needed, before calling vm_page_sbusy().

Tested by:	pho, jkim
Sponsored by:	The FreeBSD Foundation
Make also the features of the association 64-bit.
When exporting to xinpcb, just export the lower
32-bit. Using there also 64-bits will break the
ABI and will be committed separetly.

MFC after: 2 weeks
X-MFC with: 254248
Rename definition of HYPERVISOR_VIRT_START to avoid conflict with
upstream Xen definition found in xen/interface/arch-x86/xen-x86_32.h.

Submitted by:	Roger Pau Monné
Reviewed by:	gibbs
MFC after:	2 weeks
Export the inpcb features as a 64-bit entity.
Bump __FreeBSD_version to 1000048 since the
modified structure is user visible and used
by netstat, for example.
Update the manual page for vm_page_grab(9).

Reviewed and edited by:	alc
Sponsored by:	The FreeBSD Foundation
Set the back pointer from the prefix to the interface before adding
the prefix to the interface's prefix list.  This shouldn't make a
difference, since rtadvd(8) is single-threaded, but I've seen it crash
in delete_prefix() with pfx_rainfo == NULL, and this is the only place
where a prefix can be added to the list with a NULL pfx_rainfo.

MFC after:	3 days
Import NetBSD libexecinfo 20130822 to contrib
Remove accidental import of libexecinfo at wrong directory level
Import NetBSD libexecinfo 20130822 to contrib
FreeBSD compatibility for libexecinfo