Parse "inherit" for properties directly, instead of in the property parsers
Parse "inherit" for properties directly, instead of in the property parsers

All properties can be "inherit" per
https://www.w3.org/TR/SVG/propidx.html - so, parse that in a
parse_property() function instead of doing the same thing for all
concrete property parsers.

GNOME/librsvg,GNOME/librsvg,GNOME/librsvg,GNOME/librsvg