vantages: fix URL, perl dependencies, compilation on >= 10.9

[mojca (Mojca Miklavec)]

When working on #48365 I came across vantages with a number of issues:

• I'm unable to find its homepage (OK, I didn't try too hard).
• It doesn't compile on systems with libc++.
• The file /opt/local/bin/vant-setup (and a few others) use the following code where dependency on port:p5.16-term-readkey is pretty much useless:

  #!/usr/bin/perl -w
  
  use strict;
  use Getopt::Std;
  use File::Basename;
  use Term::ReadKey;
  

So the dependency on a Perl module should probably be a runtime one, but I'm sure it cannot work the way it is set up at the moment.

[dbevans (David B. Evans)]

vantages was a software suite written by Eric Osterweil while a graduate student at UCLA's Internet Research Lab. I believe the intent was to illustrate some issues with DNSSEC as well as implement corresponding proposed DNSSEC enhancements. He graduated in 2010 and vantages seems to have fallen by the wayside since then. ​Upstream development has vanished AFAICT and links from the ​IRL's web page as well as ​Osterweil's old UCLA web page are broken.

Probably better to remove this obsolete port rather than spend time trying to fix it.

[dbevans (David B. Evans)]

Removed in r143481.

[mojca (Mojca Miklavec)]

Thanks a lot. There is a lot more software like that in MacPorts, but it's hard to say which one is obsolete without doing some research on each and every one of them.