Fixing a typo.

Submitted by:	Benedikt Steinbusch (benedikt.steinbusch@googlemail.com)
Approved by:	sbruno (mentor)
MFV r249496,249498.  The most visible change is that we no longer shuts
down the connection when stdin closes, by default.  This matches Hobbit's
original netcat and GNU netcat.

Old behavior can be restored with the new -N flag.

MFC after:	2 weeks
Use arc4random() instead of random().

MFC after:	2 weeks
Although we perform path compression to reduce the height of the trie and
the number of interior nodes, we have previously created a level zero
interior node at the root of every non-empty trie, even when that node is
not strictly necessary, i.e., it has only one child.  This change is the
second (and final) step in eliminating those unnecessary level zero interior
nodes.  Specifically, it updates the deletion and insertion functions so
that they do not require a level zero interior node at the root of the trie.
For a "buildworld" workload, this change results in a 16.8% reduction in the
number of interior nodes allocated and a similar reduction in the average
execution time for lookup functions.  For example, the average execution
time for a call to vm_radix_lookup_ge() is reduced by 22.9%.

Reviewed by:	attilio, jeff (an earlier version)
Sponsored by:	EMC / Isilon Storage Division
fix a bug in the computation of the userspace offset for a give netmap buffer.

Submitted by: Hugh Nhan
Switch lagg(4) statistics to counter(9).

The lagg(4) is often used to bond high speed links, so basic per-packet +=
on statistics cause cache misses and statistics loss.

Perfect solution would be to convert ifnet(9) to counters(9), but this
requires much more work, and unfortunately ABI change, so temporarily
patch lagg(4) manually.

We store counters in the softc, and once per second push their values
to legacy ifnet counters.

Sponsored by:	Nginx, Inc.
Introduce a symbol for the GEOM class name instead of using the ad-hoc string
constant.
Introduce glabel labels based on GEOM ident attributes. In this initial
implementation, error on the side of conservatism and only create labels
for GEOMs of classes DISK and MULTIPATH.

Discussed with:	trasz
Approved by:	silence from freebsd-geom@