flatsurf/flatsurf: 3.7.0

Added:

• Added SaddleConnection::ccw().

• Added SaddleConnectionsIterator::skip() to explicitly backtrack in saddle connection search.

• Added Path::tighten().

Fixed:

• Allow build with fmt library version 6, 7, or 8.
• Changed ordering produced by flatsurf::detail::VectorExact<>::CompareSlope so it identifies infinite slopes, i.e., (0, 1) and (0, -1).
• A Path can now contain arbitrary turns. Before it was limited to the turn angles that show up in the perimeters of components.