message: Remove `using namespace NAS2D;` from MapViewState.cpp
diff: #pragma warning(disable : 4244) // possible loss of data (floats to int and vice versa)
  -using namespace NAS2D;
  -
  -
  const std::string MAP_TERRAIN_EXTENSION = "_a.png";
  const std::string MAP_DISPLAY_EXTENSION = "_b.png";
  