Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Use variable-sized arrays where appropriate.

Fix variable name in comment num=>alen. (Lost part of commit rev 1.2)

MFC after: 3 days

/* -> /*- for license, minor formatting changes

Get rid of the deprecated *LEN constants in favour of the new
*SIZ constants that include the trailing \0 byte.

Made the Ethernet address parse type standard.

OK'ed by: archie

Use a single style of multiple inclusion protection for Netgraph headers.

Reviewed by: archie, harti, emax

Fix GCC warnings caused by initializing a zero length array. In the process,
simply things a bit by getting rid of 'struct ng_parse_struct_info' which
was useless because it only contained one field.

MFC after: 2 weeks

Go back to using data_len in struct ngpppoe_init_data after discussions
with Julian and Archie.

Implement a new ``sizedstring'' parse type for dealing with field pairs
consisting of a uint16_t followed by a data field of that size, and use
this to deal with the data_len and data fields.

Written by: Archie with some input by me
Agreed in principle by: julian

Since neither archie nor I work at Whistle any more, change our email
addresses to be the more usefu @freebsd.org ones
so we can keep getting bug-reports.
- man pages to follow..

- Add new unsigned and hex integer parse types
- Fix bug in commented example code

Fix typo: "ng_parse_fixedsstring_info" -> "ng_parse_fixedstring_info"

Add more comments describing how to use parse types and how they work.

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