[librsvg] (14 commits) ...Merge branch 'cascade'

[Federico Mena Quintero <federico src gnome org>]

Summary of changes:

  389e5b7... Stylesheet.get_matches() - renamed, and return a vec of Dec
  b4558d1... Extract function to run the main cascade
  fc9721a... get_matches() doesn't need to be public anymore
  8123633... Use matches_selector() instead of matches_selector_list() s
  b0885e4... Consider specificity during matching
  7e70013... Create the MatchingContext only once per element
  1277fc3... Adjust docs
  d4599a4... Store a Stylesheet's origin (UserAgent, User, Author)
  c7197eb... Copy the stylesheet's origin into the Match struct
  85fb096... Impl Ord for Match and for Origin
  04d900d... Remove unused error variant
  8edc869... Allow unused variants for Origin, since we are only using A
  fe1d09b... Remove content_style_type() after all
  58ee9ea... Merge branch 'cascade'