xv and png

[Rainer Müller]

Ryan Schmidt wrote:
> Well, that is contrary to the FAQ, which explains why MacPorts uses  
> its own libraries in most cases. libpng is not a library for which we  
> should be making an exception to this rule.

We have a lot of dependencies like this. That's why we have this lib: 
thing at all. If the maintainer wants to manage this, it is ok to use 
it. But there is no general rule to use stuff from outside or 
'overwrite' dependencies.

Rainer