Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

/*- or .\"- or #- to begin license clauses.

Modernization effort for bin/c*:

o __P has been reoved
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
they already are.

Approved by: arch@, new style(9)

Constify and lockdown with WARNS=2.

Submitted by: Mike Barcroft <mike@q9media.com>
MFC after: 2 weeks

$Id$ -> $FreeBSD$

This commit was generated by cvs2svn to compensate for changes in r23449,
which included commits to RCS files with non-trunk default branches.

Import Jason Thorpe's contribution for an updated SCSI media changer
device (now, finally!).