o Use new-style prototypes exclusively rather than the old foo() style.
o Use new-style function definitions.
o remove register
o make functions passed to signal have the right signature.
o do minor const poisoning.
friends are terminated and allow for a maximum
host name length of MAXHOSTNAMELEN - 1.
Put parenthesis around sizeof args.
Make some variables static.
Fix telnetd -u (broken by my last commit)
Prompted by: bde
Removed getuid() root check so ntalkd can be run from a tty sandbox.
It isn't suid root anyway, who knows why the getuid() check was even
in there in the first place!
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.