Consider warning on no texture suffix (_X)

[Guekka]

honestly, it might annoy people but if a texture doesn't end in any convention suffix i'd want to know that.
eg if its just [filename].dds with no _X that makes it unclear as to what it is

From Robert, Skyblivion developer

I agree with this reasoning, but the impact would probably be too large, as most diffuse textures do not have any suffix