Serene 0.6 发布，JAXP 数据验证引擎

Serene 是一个数据验证引擎，实现了 JAXP 1.3 验证框架API，用于 RELAX NG 。

Changes: This release concentrates on further improving message quality. The accent is on error interpretation and reporting. Several bugs were fixed, and a new feature added