Match texture function fixed

I have just fixed the match texture function in the material editor. Since the new material editor was introduced this function was broken, but it is working again. With this function you can look for the same texture, with a different name in the specified texture folder.

I hope to finalize the new material editor in the next couple of days. So that means I want to finish the drawcall minimizer improvements and do some more robustness checks for the material editor in general.

Another nice feature I introduced today is a function that can replace a material with double sided property set by additional triangles. This means a separate triangle is made for both sides. Sometimes it can be more efficient to have a few more triangles if that means you can reduce the amount of drawcalls.