netpbm: "Super Stable" -> "Advanced" -- please test

[Thomas Klausner <tk%giga.or.at@localhost>]

Hi!

Currently, pkgsrc is using the "Super Stable" version of netpbm, which
only gets minimal fixes. The author is also maintaining an "Advanced"
version, and I've been feeding back our local patches to him.

I'd like to switch pkgsrc to the "Advanced" version.

I've prepared a version in wip/netpbm. Please test it on your favorite
platform/opsys. I'll use it for updating graphics/netpbm sometime next
week, depending on the feedback I get.

Thanks,
 Thomas