Improve reliability of incrementing list-item counter; release 2.6!

Ensure newline-collapse settings are preserved, code tidies regarding whitespace collapsing.

Add speak-as support in counter-styles, some codestyle improvements.

Correct inherieance to include unmodified counters.

Add support for marker-side property.

Corrections for display: list-item.
1. It's display: list-item, not display: list
2. Insert an implicit counter-increment: list-item

Preprocess away lists, add builtin ::before/::after support.

Adjust cascade shorthand to feed pseudoelements to the property parsers,
now that Stylist Traits provides the APIs for it.

Implement counter-styles into counters infrastructure.

Move shorthand utils into Stylist Traits & switch to matching license.

Add new support APIs to Stylist Traits, releasing v0.1.2!

Expose pseudoelements to PropertyParsers.
Add utility for parsing unordered shorthands.

Parse longhand list-style property.

Parse list-style longhand properties, tweak counter-lookup.

Test & fix rendering of Ethiopian 1.

Simplify counterstyle API & implementation.

Test & fix rendering ethiopian numbers.

Draft Ethiopic numbering implementation.

Add support for chinese, with correction regarding handling negatives.

Minor corrections to counter rendering.

Unit tests & bug fixes for counter-renderers.