Version 2.45.90
- New API functions:
    rsvg_handle_render_document()
    rsvg_handle_render_layer()
    rsvg_handle_render_element()
    rsvg_handle_get_geometry_for_layer()
    rsvg_handle_get_geometry_for_element()

  CairoRenderer in the librsvg_crate has corresponding functions
  as well.

- Fix builds with gettext ≥ 0.20 (Ting-Wei Lan).

- If the C API is called out of order, downgrade hard panics to
  g_critical() to cope with incorrect/old applications that called
  rsvg_handle_get_dimensions() before rsvg_handle_close().

- API reference documentation is much improved.