Import restorecd-5.0.1-20090818 files.

Announced as the following on port-cobalt:
http://mail-index.netbsd.org/port-cobalt/2009/08/18/msg000337.html

 - use 5.0.1 release binaries and rebuild paneld on it
 - remove unused and obsolete .cshrc in data/common
 - remove unnecessary 'size=N' field (which has been added after 5.0)
   from spec file for mtree(8) to create ISO image with patched files
Import restorecd-5.0.2-20100218 files.

Announced as the following on port-cobalt:
http://mail-index.netbsd.org/port-cobalt/2010/02/19/msg000415.html

 - use 5.0.2 release binaries and rebuild paneld on it
 - prepare proper boot.cfg menu on booting i386 server
 - remove obsolete cksum files per releasedir changes
Import restorecd-5.1_RC1-20100506 files.

Announced as the following on port-cobalt:
http://mail-index.netbsd.org/port-cobalt/2010/05/07/msg000423.html

 - use 5.1_RC1 binaries and rebuild paneld on it
 - update MAKEDEV and named files per release branch
Import restorecd-20100525 files.

Announced as the following on port-cobalt:
http://mail-index.netbsd.org/port-cobalt/2010/05/27/msg000424.html

 - use 5.2_RC2 binaries and rebuild paneld on it
 - remove unnecessary options from makefs on creating iso image
Import restorecd-5.1_RC4-20100918 files.

Announced as the following on port-cobalt:
http://mail-index.netbsd.org/port-cobalt/2010/09/18/msg000448.html

 - use 5.1_RC4 binaries and rebuild paneld on it
Import restorecd-5.1-20101114 files.

Announced as the following on port-cobalt:
http://mail-index.netbsd.org/port-cobalt/2010/11/19/msg000453.html

 - use 5.1 release binaries and rebuild paneld on it
 - update inetd.conf and rc.conf files per release
 - explicitly set no_swap=yes on cobalt installation to avoid a warning
 - explicitly set mountnfs=yes on cobalt installation
 - remove more obsolete cksum files from spec file per releasedir changes