loadimage show pcx error

[a740g]

@macalwen I figured out the issue. It is indeed a limitation with dr_pcx. And I also figured out that other than the issues you reported, it does not support loading 24bpp images too. So, what I said on top earlier about 24bpp images working is incorrect. Probably that was something else I tested.

Anyway, I am in the process of writing the missing parts and if I get too adventurous, I might end up writing a new loader.

Thank you for reporting the issue.