Changed IEnumerable<> to IReadOnlyList<> in public interfaces where possible; removed ToReadOnly calls to avoid unnecessary allocations when iterated by index; made CssStyleRule sort data after parsing, not on every call to property
Converted instance Items properties to static TraverseList methods to avoid NRE
CSS to Css file name fix (part 1)
CSS to Css file name fix (part 2)
Added CssRuleKind generation, changed CAPS_CASE to PascalCase; added [All]*Rules props to CssStyleSheet
CSS to Css file name fix (part 3)