Using non-binary ply export as default

wrap/io_trimesh/export_ply.h

@@ -89,7 +89,7 @@ public:
     static int Save(const SaveMeshType &m,
                     const char *filename,
                     int savemask,
-                    bool binary = true,
+                    bool binary = false,
                     CallBackPos *cb = 0)
     {
         PlyInfo pi;