[MiNT] libpng 1.5.9

[m0n0 <ole@monochrom.net>]

Hello there,

maybe some people remember a disucssion about libpng 1.5.x about an 
year ago. The problem with 1.5.x was the usage of setjmp...

It was nested within another macro. That caused problems. Today I gave 
it another try. It compiles cleanly. It works well with
netsurf. Looks like the problem vanished. I don't know the reason, 
maybe libpng, gcc or the mintlib changed something.
Or maybe some odd flag was removed from the build tree.

Yes, you could also compile libpng 1.5 before for Atari, but one had to 
disable setjmp() stuff. (Look at grafx source,
there it also done).

So, now it looks like we can put up an libpng 1.5 rpm for sparemint :)

Greets,
m