Document iSNS defaults.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Import in latest mtree from NetBSD to fix a bug in parsing group files
that jmg fixed upstream.

MFC after:	1 week
Sponsored by:	DARPA, AFRL
Always request a completion for every work request for iWARP.  The
initial MPA exchange must be tracked this way so that t4_tom's state for
the tid is all clean at the time the tid transitions to RDMA mode.  Once
it does, t4_tom is out of the way and iw_cxgbe uses the qp endpoints
directly.

Sponsored by:	Chelsio Communications
Make the GPIO children attach to the first unit available and not only to
unit 0.

It seems that this 'simplification' was copied to all GPIO drivers in tree.

This fix a bug where a GPIO controller could fail to attach its children
(gpioc and gpiobus) if another GPIO driver attach first.
Rework virtual machine hypervisor detection.
- Move the existing code to x86/x86/identcpu.c since it is x86-specific.
- If the CPUID2_HV flag is set, assume a hypervisor is present and query
  the 0x40000000 leaf to determine the hypervisor vendor ID.  Export the
  vendor ID and the highest supported hypervisor CPUID leaf via
  hv_vendor[] and hv_high variables, respectively.  The hv_vendor[]
  array is also exported via the hw.hv_vendor sysctl.
- Merge the VMWare detection code from tsc.c into the new probe in
  identcpu.c.  Add a VM_GUEST_VMWARE to identify vmware and use that in
  the TSC code to identify VMWare.

Differential Revision:	https://reviews.freebsd.org/D1010
Reviewed by:	delphij, jkim, neel
Treat IFS separators in "$*" as quoted.

This makes a difference if IFS starts with *, ?, [ or a CTL* byte.
Filter out TESTS_SUBDIRS already added to SUBDIR instead of blindly
appending the TESTS_SUBDIRS variable to SUBDIR

Duplicate directory entries can cause unexpected side effects, like
installing the same files multiple times. This can be easily
reproduced via the following testcase prior to this commit:

  SUBDIR= dir
  TESTS_SUBDIRS+= dir

  .include <bsd.test.mk>

Sponsored by: EMC / Isilon Storage Division