Remove svn:mergeinfo from the releng/10.0 branch.

After branch creation from stable/10, the stable/10 branch mergeinfo
was moved to the root of the branch.

Since there have not been any merges from stable/10 to releng/10.0
yet, we do not need to track any of the existing mergeinfo here.

Merges to releng/10.0 should now be done to the root of the branch.

For future branches during the release cycle, unless otherwise noted,
this change will be done as part of the stable/ and releng/ branch
creation.

Discussed with: peter
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

- 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

MFC r257917:

Fix typo in "iscsictl -v".

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

MFC r257379:

Rename '-h' option to '-p', and use "portal" instead of "host" or "address",
in order to be consistent with iSCSI terminology. Besides, calling the
option '-h' was just wrong.

This changes usage for newly added iscsictl(8), and two newly added
subcommands to ctladm(8). This breaks POLA between CURRENT and 10,
but since 10.0 has not been released yet, it's still ok to do.

MFC r257380:

Bump .Dd after r257379.

Approved by: re (glebius)
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

Make iscsictl(8) automatically try to load the iscsi module. While here,
improve module loading in iscsid(8) and ctld(8).

Approved by: re (delphij)

Minor mdoc fixes.

Approved by: re (blanket)

Bring in the new iSCSI target and initiator.

Reviewed by: ken (parts)
Approved by: re (delphij)
Sponsored by: FreeBSD Foundation