Fixed TextureTypeToString defined multiple times.

- Moved TextureTypeToString to it's own file.
- Added new file to CMakeLists.txt.
- Added 6 missing values in TextureTypeToString.
- Added 6 missing aiTextureType enum values in assimp_cmd/Info.cpp.

tools/assimp_cmd/Info.cpp

@@ -444,6 +444,12 @@ int Assimp_Info (const char* const* params, unsigned int num) {
 			aiTextureType_DISPLACEMENT,
 			aiTextureType_LIGHTMAP,
 			aiTextureType_REFLECTION,
+			aiTextureType_BASE_COLOR,
+			aiTextureType_NORMAL_CAMERA,
+			aiTextureType_EMISSION_COLOR,
+			aiTextureType_METALNESS,
+			aiTextureType_DIFFUSE_ROUGHNESS,
+			aiTextureType_AMBIENT_OCCLUSION,
 			aiTextureType_UNKNOWN
 		};
 		for(unsigned int type = 0; type < sizeof(types)/sizeof(types[0]); ++type) {