Let's avoid using md5 as checksum

[Rainer Müller]

js wrote:
> As you know, MD5 has serious flaws (http://en.wikipedia.org/wiki/MD5)
> So recently I don't use it and even  remove it when I found it in the
> checksum part of portfile.
> I thought dropping use of md5 in portfile would be nice.
> 
> Any thought?

I don't think these flaws are strong enough to discourage use of MD5 as 
a hashsum for file verification yet.

Rainer