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.
do it themselves. (Some of these programs actually depended on this
beyond compiling the definition of struct ifinfo!) Also fix up some
other #include messes while we're at it.
fix return/exit codes in some cases.
Add -S which will delete any old entry first.
Add "auto" in proxy case, so it finds the right interface automatically.
flag. The getopt handling in here is actually pretty bogus (not Phil's
fault - it's original sin) but the general approach is working so I'm not
going to break it. Some small tweaks of my own to add error checking to what
was originally submitted. Strange how nobody noticed that the flag was
documented but completely missing from the code before! [jkh].
Submitted by: Phil Taylor <phil@zipmail.co.uk>