[K12OSN] (final) pre-release ISOs ready for testing

[Eric Harrison]

Barring the discovery of a show-stopping bug, this is it. I intend to
release these ISOs as the official 4.2.1 release on Thursday.

   ftp://k12linux.mesd.k12.or.us/pub/K12LTSP/4.2.1/iso/

   rsync -Pave ssh k12linux.mesd.k12.or.us::K12LTSP-pre/* .


-Eric