- 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

Refactor disk disconnection and geom destruction handling sequences.
Do not close/destroy opened consumer directly in case of disconnect. Instead
keep it existing until it will be closed in regular way in response to
upstream provider destruction. Delay geom destruction in the same way.
Previous implementation could destroy consumers still having active
requests and worked only because of global workaround made on GEOM level.

Remove trailing spaces.

- Add md_provsize field to metadata, which will help with
shared-last-sector problem.
After this change, even if there is more than one provider with the same
last sector, the proper one will be chosen based on its size.
It still doesn't fix the 'c' partition problem (when da0s1 can be confused
with da0s1c) and situation when 'a' partition starts at offset 0
(then da0s1a can be confused with da0s1 and da0s1c). One can use '-h'
option there, when creating device or avoid sharing last sector.
Actually, when providers share the same last sector and their size is equal,
they provide exactly the same data, so the name (da0s1, da0s1a, da0s1c)
isn't important at all.
- Provide backward compatibility.
- Update copyright's year.

MFC after: 1 week

- Introduce option for hardcoding providers' names into metadata.
It allows to fix problems when last provider's sector is shared between few
providers.
- Bump version number for CONCAT and STRIPE and add code for backward
compatibility.
- Do not bump version number of MIRROR, as it wasn't officially introduced yet.
Even if someone started to play with it, there is no big deal, because
wrong MD5 sum of metadata will deny those providers.
- Update manual pages.
- Add version history to g_(stripe|concat).h files.

Change naming scheme from /dev/<name>.concat to /dev/concat/<name>.

- Add 'stop' command, which works just like 'destroy' command, but sounds
less dangerous.
- Update manual pages and extend examples.
- Bump versions.

- Teach CONCAT class how to talk with geom(8).
- Remove provider if any disk was lost.
- Dump CONCAT version.

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

Print a space character between string given as a macro argument and
bio description.

Correct year in copyrights.

- Remove d_valid field, we can use d_consumer field to check if disk
is valid.
- Use SYSCTL_DECL() instead of using own, ugly extern.

Removed unused fields.

Remove unused field.

Approved by: scottl (mentor)

Introduce CONCAT GEOM class for disk concatenation.
It allows manual and automatic (based on on-disk metadata) concatenation.

Reviewed by: phk, scottl
Approved by: scottl (mentor)