sprintf replacement: introduce au_snprintf to support snprintf for v2013

and earier ( closes https://github.com/assimp/assimp/issues/743 )

code/MDLMaterialLoader.cpp

@@ -47,6 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 // internal headers
 #include "MDLLoader.h"
 #include "MDLDefaultColorMap.h"
+#include "StringUtils.h"
 #include "../include/assimp/texture.h"
 #include "../include/assimp/IOSystem.hpp"
 #include "../include/assimp/DefaultLogger.hpp"
@@ -699,7 +700,7 @@ void MDLImporter::ParseSkinLump_3DGS_MDL7(
 
         // place this as diffuse texture
         char szCurrent[5];
-        ::snprintf(szCurrent,5,"*%i",this->pScene->mNumTextures);
+        ai_snprintf(szCurrent,5,"*%i",this->pScene->mNumTextures);
 
         aiString szFile;
         const size_t iLen = strlen((const char*)szCurrent);