WARNING: Redesigned structs

- Mesh, Shader, Material structs have been reviewed to minimize size when passed by value, all required code has been reviewed.
 - GetCollisionRayModel() reviewed to avoid pointer, not required because model is not modified inside the function
 - UnloadMesh() reviewed, pointer not required
 - CheckCollisionRay*() parameters name reviewed

examples/models/models_obj_viewer.c

@@ -54,7 +54,7 @@ int main(void)
             {
                 if (IsFileExtension(droppedFiles[0], ".obj"))
                 {
-                    for (int i = 0; i < model.meshCount; i++) UnloadMesh(&model.meshes[i]);
+                    for (int i = 0; i < model.meshCount; i++) UnloadMesh(model.meshes[i]);
                     model.meshes = LoadMeshes(droppedFiles[0], &model.meshCount);
                     bounds = MeshBoundingBox(model.meshes[0]);
                 }