Use getpwnam before getpwuid since two users with same uids can exists
(affects new login classes code only)
The same fixes as in inetd: by default run `system crontab things' with
daemon login class now, not restrict them to user class breaking
compatibility with old way (so-called nobody limits problem)
Implement user[:group][/login-class] syntax in system crontab
for more flexible control (the same as in inetd)
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.