ANNOUNCE: Version 4.21 released

[MW Mike Weiner (5028)]

D'UH, i am sorry, after a bit more review, it does appear that the
install.sh script does an RPM install .. missed that before (lack of
caffeine dyslexia). 

But i do see a potential issue, reminds me of what redhat did to the mysql
installs. The original RPMS were mailscanner, and the new ones are
MailScanner - my last experience with RedHat-MySQL was similar (redhat
packages were mysql and MySQL's were MySQL and that caused some rpm -Uvvh
problems). I just want to be sure i dont break an already working
"production" install.

Thanks
Michael Weiner