Version 2.46.0

- The following are highlights compared to the 2.44.x series.  For
  full details, please see the release notes for the 2.45.x series.

- All of librsvg.so is now implemented in Rust!  That is, except for a
  very thin wrapper over the public API functions.  Hopefully we can
  remove this wrapper when Cargo gets some more features around
  controlling the linking step.  This release requires at least Rust 1.34.

- Librsvg now comes with a Rust crate that can be used from Rust
  applications.  See librsvg_crate/examples.  This Rust API is
  designed to be idiomatic; if you want a Rust binding to the shared
  library instead, please use the "rsvg-rs" crate from crates.io.

- The following API functions are new in the C library:
    rsvg_handle_get_intrinsic_dimensions()
    rsvg_handle_render_document()
    rsvg_handle_render_layer()
    rsvg_handle_render_element()
    rsvg_handle_get_geometry_for_layer()
    rsvg_handle_get_geometry_for_element()

  Correspondingly, there is a new chapter in the documentation, called
  "Recommendations for Applications".  These new APIs conform better
  with the web platform's idea of how SVG sizing/positioning should
  work.  Applications should now find it easier to scale and render
  SVGs in a single call, instead of having to obtain image dimensions
  first.

- A bunch of functions have been deprecated but are still available:

    - rsvg_handle_write()/close() are deprecated in favor of the
      stream functions.  Unfortunately the write()/close() pair
      require buffering the entire document, in case it is a .svgz
      compressed file; the streaming functions do not have this
      problem.

    - Functions that return RsvgDimensionData and RsvgPositionData are
      deprecated, since they just use integers instead of floating
      point numbers.  They are replaced with the _get_geometry_*()
      functions above.

- The library is a lot more strict now in terms of detecting that the
  API functions are called in the correct order.  For example, calling
  rsvg_handle_get_dimensions() before rsvg_handle_close() will now
  emit a critical warning.

- Librsvg is gradually moving towards using code from Mozilla's Servo.
  We haven't quite gotten rid of libcroco and libxml2 yet, but this is
  in progress.

- Many thanks to all the people who participated in the long cycle for
  2.45.  Having the whole library's functionality in Rust is a big
  accomplishment!