remove combined {models,sprites}.mat, remove extra .mdl .spr exts

valve/pbr/models/w_oxygen.mdl/w_oxygen.mat

@@ -0,0 +1,40 @@
+
+{
+"for" "#models/w_oxygen/back.mdl"
+//"basecolor_map" "back.png"
+//"normal_map" "back_normal.png"
+//"metal_map" "back_metal.png"
+//"roughness_map" "back_roughness.png"
+}
+
+{
+"for" "#models/w_oxygen/chromebump.mdl"
+//"basecolor_map" "chromebump.png"
+//"normal_map" "chromebump_normal.png"
+//"metal_map" "chromebump_metal.png"
+//"roughness_map" "chromebump_roughness.png"
+}
+
+{
+"for" "#models/w_oxygen/chrome_scratch.mdl"
+//"basecolor_map" "chrome_scratch.png"
+//"normal_map" "chrome_scratch_normal.png"
+//"metal_map" "chrome_scratch_metal.png"
+//"roughness_map" "chrome_scratch_roughness.png"
+}
+
+{
+"for" "#models/w_oxygen/highlightchrome.mdl"
+//"basecolor_map" "highlightchrome.png"
+//"normal_map" "highlightchrome_normal.png"
+//"metal_map" "highlightchrome_metal.png"
+//"roughness_map" "highlightchrome_roughness.png"
+}
+
+{
+"for" "#models/w_oxygen/wing.mdl"
+//"basecolor_map" "wing.png"
+//"normal_map" "wing_normal.png"
+//"metal_map" "wing_metal.png"
+//"roughness_map" "wing_roughness.png"
+}