[librsvg] (24 commits) ...Merge branch 'stop-color-and-opacity'

[Federico Mena Quintero <federico src gnome org>]

Summary of changes:

  7a0b270... Remove AllowInherit and AllowCurrentColor from color parsin
  cd704ac... Use cssparser::Color instead of our own Color enum
  35f0c63... Move stop_color to Rust
  9a46909... opacity.rs: Use UnitInterval instead of f64
  6022180... Move stop_opacity directly to Rust
  44cf1cb... Don't pass a state to rsvg_rust_cnode_new(); create it righ
  76280c2... Remove superfluous "switch" statement
  ea48148... draw_path_builder: Take in an already-derived RsvgState; do
  54a6a8b... draw_pango_layout(): Take in an RsvgState; don't obtain it 
  4c594c7... draw_surface(): Take in an RsvgState; don't obtain it from 
  c3a52ce... add_clipping_rect(): Take in an affine; don't get it from t
  98b7baa... shapes.rs:render_path_builder() - Take in an already-inheri
  a38be40... NodeTrait::draw() - take in an already-inherited RsvgState
  1bd9152... NodeImage::draw(): Use the passed-in state
  cb2bf9a... text.rs: Pass around the state from the draw() method
  97e22ec... For now, ignore pservers-grad-18-b.svg
  f6ed51e... rsvg_state_new_with_parent(): Don't do reinheritance here; 
  10f1855... Remove rsvg_state_reinit()
  21dd793... Move state->parent to Rust.  This is the last field!
  8cad4b1... Fix two leaks of states in the filters that need to reconst
  a133ec4... Completely move RsvgState to Rust
  1354e38... Replicate the old rsvg_state_clone() behavior with a little
  701630e... NodeUse: push discrete layer, *then* push a new state to fr
  18c35f1... Merge branch 'stop-color-and-opacity'