Report missing or assets with wrong capitalization

Mods who provide gfx assets break when zipped (and presumably don't work on linux and osx) because the game looks in these cases for case sensitive assets ex Path\file.dds and if the actual path is path\file.dds it will fail to be loaded.

This is especially annoying because people report this as Irony bug rather than an issue with the mod (which it actually is).