Support the font-feature-settings property
The font-feature-settings
property from the CSS Fonts Module Level 3 makes it possible to access a boatload of OpenType features like small caps, alternate glyph forms, etc.
Apparently we can just take the value of this property and feed it to pango_attr_font_features_new()
. Librsvg already sets Pango attributes like this; maybe we just need to add that property there.
See also #668 (closed) for support for small-caps.