dmg names

[Ryan Schmidt]

Currently we have

MacPorts-1.5.0-10.3.dmg
MacPorts-1.5.0-10.4.dmg
MacPorts-1.5.0-10.5.dmg

These names are rather similar and people have in the past not  
realized that these are for different OS versions.

Maybe we could use the kitty name starting with our next release?

MacPorts-1.6.0-Panther.dmg
MacPorts-1.6.0-Tiger.dmg
MacPorts-1.6.0-Leopard.dmg

That would make it easier to distinguish between the different  
images. Note that Apple has been using this kind of naming for some  
time already in its security updates, and now also in the QuickTime  
7.3 disk images.