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)

Find places to store the previously implicityly passed unit number in
the three configuration ioctls which need a unit number.

Add a "ccd.ctl" device for config operations.

Implement ioctls on ccd.ctl which rely on the explicityly passed
unit numbers.

Update ccdconfig to use the new ccd.ctl interface.

Add code to the kernel to detect old ccdconfig binaries, and whine
about it.

Add code to ccdconfig to detect old kernels, and whine about it.

These two compatibility measures will be retained only for a limited
period since they are in the way of GEOM'ification of ccd.

This commit was generated by cvs2svn to compensate for changes in r13047,
which included commits to RCS files with non-trunk default branches.

Oops, forgot pathnames.h.