message: Use absolute depth rather than relative depth offset
diff: @@ -203,7 +203,7 @@ void MapViewState::diggerTaskFinished(Robot* robot)
  Direction dir = static_cast<Robodigger*>(robot)->direction(); // fugly
  NAS2D::Point<int> origin = t->position();
  - int depthAdjust = 0;
  + int newDepth = t->depth();
  if(dir == Direction::DIR_DOWN)
  {
  @@ -215,10 +215,10 @@ void MapViewState::diggerTaskFinished(Robot* robot)
  as2->ug();
  NAS2D::Utility<StructureManager>::get().addStructure(as2, mTileMap->getTile(origin, t->depth() + 1));
  - depthAdjust = 1;
  + ++newDepth;
  mTileMap->getTile(origin, t->depth())->index(TerrainType::TERRAIN_DOZED);
  - mTileMap->getTile(origin, t->depth() + depthAdjust)->index(TerrainType::TERRAIN_DOZED);
  + mTileMap->getTile(origin, newDepth)->index(TerrainType::TERRAIN_DOZED);
  /// \fixme Naive approach; will be slow with large colonies.
  NAS2D::Utility<StructureManager>::get().disconnectAll();
  @@ -249,7 +249,7 @@ void MapViewState::diggerTaskFinished(Robot* robot)
  for (const auto offset : DirectionScan3x3)
  {
  const auto position = origin + offset;
  - mTileMap->getTile(position, t->depth() + depthAdjust)->excavated(true);
  + mTileMap->getTile(position, newDepth)->excavated(true);
  }
  checkRobotSelectionInterface(constants::ROBODIGGER, constants::ROBODIGGER_SHEET_ID, RobotType::ROBOT_DIGGER);
  