Port request: pngout (image compression)

[Torsten Zühlsdorff]

Hello Murk,

> Thank you sir -- great stuff!

You're welcome :)

Sadly i'm still waiting for a response addressing the license questions.

Also i wasn't able to fix deskutils/ladon because of its npm 
dependencies. But this is needed to get jpeg-compress into the ports.

My last idea is providing a precompiled version of ladon. This is not 
wanted in the portstree by default, but there are some exceptions from 
this rule. I will test if the port works this way and let the committer 
decide if this is acceptable as a workaround.

Greetings,
Torsten