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

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

Unnest includes before forthcoming editing.

Add a GraphViz-exporting ngctl(8) "dot" command. You can now create
very useful .dot files of your netgraph(4) to quickly visualize the
nodes, hooks and edges. An example of this can be found here:
http://people.freebsd.org/~green/sample-netgraph-dot.ps
If anyone would like to refine the output further, please do so.

Add ngctl "write" command.

MFC after: 1 week

Unrevert something which shouldn't have been reverted in the previous revert.

(Yes, I'm going to bed now to get some much needed sleep...)

Backout my previous commit, it appearantly doesn't work for asynchronous
messages.

Experiemntal ascii based device configuration mechanism.

This may or may not survive, decision will be made well before 5.0-R

When the 'msg' command is used from the command line, check for a
synchronous reply, and display it (if any) before exiting.

Requested by: phk

No need to try loading ng_socket.ko, as NgMkSockNode() does that
for us now if necessary.

Add two new generic control messages, NGM_ASCII2BINARY and
NGM_BINARY2ASCII, which convert control messages to ASCII and back.
This allows control messages to be sent and received in ASCII form
using ngctl(8), which makes ngctl a lot more useful.

This also allows all the type-specific debugging code in libnetgraph
to go away -- instead, we just ask the node itself to do the ASCII
translation for us.

Currently, all generic control messages are supported, as well as
messages associated with the following node types: async, cisco,
ksocket, and ppp.

See /usr/share/examples/netgraph/ngctl for an example of using this.

Also give ngctl(8) the ability to print out incoming data and
control messages at any time. Eventually nghook(8) may be subsumed.

Several other misc. bug fixes.

Reviewed by: julian

If we get an EPROTONOSUPP error when trying to create the netgraph socket
node, it's most likely because the "ng_socket.ko" KLD is not loaded yet.
So make an attempt to load it before giving up.

Put include <netgraph.h> back in - problem was due to a cvsup mess on
freefall. There may also be a real problem w/ buildworld but the fix
would go somewhere else, not here.

Cleanup missing includes, stale includes, and a few printf format
inconsistancies.

Whistle's Netgraph link-layer (sometimes more) networking infrastructure.
Been in production for 3 years now. Gives Instant Frame relay to if_sr
and if_ar drivers, and PPPOE support soon. See:
ftp://ftp.whistle.com/pub/archie/netgraph/index.html
for on-line manual pages.

Reviewed by: Doug Rabson (dfr@freebsd.org)
Obtained from: Whistle CVS tree