Remove legacy libpng 1.4 files from submodule

[Lone_Wolf]

When building oolite on linux against libpng 1.6.x one issue arises at runtime:

The submodule oolite-linux-dependencies has png.h & pngconf.h in its include folder .

Some parts of oolite use this file and request libpng 1.4.7 at runtime, making the menus unreadable.
Note that the linker correctly links to libpng 1.6 .

Removing those files before building solves the issue completely .

viewtopic.php?t=21909 has a lengthy discussion about these files.

[mcarans]

When building oolite on linux against libpng 1.6.x one issue arises at runtime:

The submodule oolite-linux-dependencies has png.h & pngconf.h in its include folder .

Some parts of oolite use this file and request libpng 1.4.7 at runtime, making the menus unreadable.
Note that the linker correctly links to libpng 1.6 .

Removing those files before building solves the issue completely .

viewtopic.php?t=21909 has a lengthy discussion about these files.

You are right. The modern build only uses the mozilla folder in there, so much of it is outdated.