RAII for auto-closing file streams

Small fixes I didn't want to include in unrelated PRs.

There are a few left in `storage.cpp` but since it's a single function
in 600 lines of code, I didn't want to touch the mess. The others are
safe to remove, cucumber and test run on Finland gives 👍.

src/benchmarks/static_rtree.cpp

@@ -45,7 +45,6 @@ FixedPointCoordinateListPtr loadCoordinates(const boost::filesystem::path &nodes
         BOOST_ASSERT((std::abs(coords->at(i).lat) >> 30) == 0);
         BOOST_ASSERT((std::abs(coords->at(i).lon) >> 30) == 0);
     }
-    nodes_input_stream.close();
     return coords;
 }