Implement style tree flattening utility.

This will be useful in Rhapsode for making sure voice synthesizers continue to
have full voice features information as the user jumps around the document.
And it will be useful for visual browsers in transitioning from layout to render.

Implement whitespace collapse, togglable via white-space: pre/normal;

Abstract Tree traversal (commited out-of-order).

Parse & prepare to handle white-space: pre;

Implement CSS3 counters.

Parse CSS counters.

Fix compilation of Assets StyleSheets.

Optimize: use HashMap.Lazy for cascade.

Provide utilities for rewriting CSS-referenced URLs.

Improve documentation, release version 1.2

Write reference documentation.

Request @import'd styles concurrently.

Let user & useragent styles query for a lack of author styles.

Introduce simplified html2css API

Which, now that these are implemented, lowers <style> to @media & <link rel=stylesheet> to @import.

Release Haskell Stylist 1.1.0.0!

Unittest conditional styles, add loadImports API to fit Rhapsode's use.

Test rules capturing of ConditionalStyleSheet.

Code cleanliness: drop unneeded ' from Data.CSS.Style.Cascade.dispatch'

Test CSS variables.

Fix: ConditionalStyles reversed CSS precedance.