Version 2.49.5

- #607 - Support the mix-blend-mode property from SVG2 and the
  Compositing and Blending Level 1 specification, so layers can be
  composited with operators like multiply/screen/color-burn, etc.
  https://www.w3.org/TR/compositing-1/ (John Ledbetter).

- #473 - Support the paint-order property from SVG2, so one can pick
  the order in which a path's fill/stroke/markers are drawn (John Ledbetter).

- Cleanups of the basic drawing and paint-handling code (Paolo Borelli).

- Many style fixes per cargo-clippy (Sven Neumann).

- Improved documentation on the library's internals.