MFS r260608:

Remove scary comment about this being a test key.

There has been no need to regenerate the signing key.

Approved by: bapt (mentor, implicit)
Approved by: re (gjb)

- 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 r257344,r257403:

Move /etc/keys to /usr/share/keys where users are less likely to modify them.

Approved by: bapt
Approved by: re (gjb)

Move /etc/keys to /usr/share/keys where users are less likely to modify them.

Requested by: secteam (cperciva, des)
Approved by: bapt

Add infrastructure for installing pkg(8) keys into /etc/keys/pkg and add
the current test key that packages will be signed with until 10.0-RELEASE.

Approved by: bapt
Discussed by: bapt with des
MFC after: 2 days