- 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 the Clang specific -Wmissing-variable-declarations to WARNS=6.

This compiler flag enforces that that people either mark variables
static or use an external declarations for the variable, similar to how
-Wmissing-prototypes works for functions.

Due to the fact that Yacc/Lex generate code that cannot trivially be
changed to not warn because of this (lots of yy* variables), add a
NO_WMISSING_VARIABLE_DECLARATIONS that can be used to turn off this
specific compiler warning.

Announced on: toolchain@

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

Obtained from: Juniper Networks

Allow classes to specify local source files.

MFC after: 3 weeks

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.

Use SHLIBDIR instead of LIBDIR. This should fix buildworld breakage.

Reported by: des

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