csspool version 0.2.4 has been released!

CSSpool (pronounced "cesspool") is a validating SAC parser for CSS. The parser
calls methods on a document handler depending on what it has found. CSSPool
currently only supports CSS 2.1. CSSPool will not yield invalid properties or
selectors.

Changes:

## 0.2.4

* Fixed error handling on at rules. Thanks Dan for tests!
* Made specificity an array
* Made StyleSheet::Rule comparable on specificity