Change behavior of terrain painter when deleting a material

Have you ever deleted a material in T3D terrain painter and had that material's assignment mysteriously jump to another material? I found a fix.

What happens is the deleted material assignment gets dropped to the next lower material. What I've done is created a rule that material 0 is default and anything in use by a deleted material gets reassigned to that.

It's not a bug fix, just my preferred method of handling this case.

terrData.cpp in function TerrainBlock::removeMaterial

//KENHACK if material is in use, reassign to default.
   //This prevents accidental assignments to other materials.
   //REPLACEMENT
   for ( S32 i = 0; i < mFile->mLayerMap.size(); i++ )
   {
	   if ( mFile->mLayerMap[i] == index )
      {
		 //assign to default   
         mFile->mLayerMap[i] = 0;
      }
	   if ( mFile->mLayerMap[i] > index && mFile->mLayerMap[i] != 0 )
      {
         mFile->mLayerMap[i]--;
      }
   }
   // ORIGINAL
   // for ( S32 i = 0; i < mFile->mLayerMap.size(); i++ )
   // {
   //    if ( mFile->mLayerMap[i] >= index &&
   //       mFile->mLayerMap[i] != 0 )
   //    {
   //          mFile->mLayerMap[i]--;
   //    }
   // }