- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add support for NetFlow version 9 into ng_netflow(4) node.

Submitted by: Alexander V. Chernikov <melifaro ipfw.ru>

o Replace disappeared URLs to Cisco docs by new ones, style.
No functional changes.

A new version of NetFlow node.

The most significant changes are:
- Use UMA zone instead of own chunk of memory.
- Lock each hash entry separately.
- Expire items "actively" - interrupt method can expire flows
from hash slot, when it searches through it.
- Remove global tailqueue. Make callout thread search through
every hash slot.
- Export datagram is detached from private data and filled. If
it is incomplete, it is attached back. Another thread will
continue working with it.

Lesser, but also important speedups:
- Flows in hash slot are stored in tailqueue. Whenever a flow is
hit, it is moved to the begging, so it can be located quicker.
- When callout thread works with hash slot it bails out if
slot mutex is contested.

- Remove advertising clause from copyright [1]
- Change my email to glebius@FreeBSD.org

Requested by: ru [1]

A netgraph node implementing Netflow version 5.

Supported by: Bestcom ISP, Rinet ISP
Approved by: julian (mentor)