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)

Rename the generic "CLASS" to the more specific "GEOM_CLASS".
While I'm here remove redundancy and inconsistencies.

Obtained from: Juniper Networks

Switch the default WARNS level for sbin/ to 6.

Submitted by: Ulrich Spörlein

Don't use version number in library name. The library version is checked
after dlopen() anyway, so we should be safe.

Suggested by: ru

After changing LIBDIR to SHLIBDIR, because of dependencies problems,
new problem shows up: symblic links (<libname>.so) are created under
/usr/lib/ now, instead of under /lib/geom/ where geom(8) looks for them.
Introduce a workaround to fix this by teaching geom(8) to open libraries
via /lib/geom/<libname>.so.<major_number> instead of /lib/geom/<libname>.so.

Various style.Makefile(5) improvements.

Inspired by: ru

Fix supposed compilation problem, using LIBDIR here can confuse core/
compilation.

Bring in geom(8) utility. It is an universal utility for operating on
GEOM classes. It works by loading a shared library via dlopen(3) mechanism
with class-specific code, it is also responsible for communicating with
GEOM via libgeom(3).
Per-class shared libraries are going to be stored in /lib/geom/ directory.
It provides also few standard commands like 'list', 'load' and 'unload'
for existing classes which aren't aware of geom(8).
More info will be send on freebsd-current@ mailing list.

Supported by: Wheel - Open Technologies - http://www.wheel.pl