Upgrade to CSS4J 0.38.1

CSS4J CHANGES
=============

Version 0.38.1
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 * Core:
- NSAC implementation: namespace support.
- NSAC implementation: the toString() method of attribute selectors was 
  unnecessarily escaping some characters.
- NSAC implementation: allow whitespace before the attribute name in attribute 
  selectors.
- NSAC implementation: first style rule after some @-rules could be lost
- Support this implementation's SAC namespaces in CSS Object Model.
- Refactor: move escapeControl from CSSStringValue to ParseHelper.
- Remove the CSSRule insertionIndex field and logic, that have not been used by 
  the cascade implementation for months.
- DOM wrapper: fix a couple NPE code paths.
- DOM wrapper: avoid NPE in user agent if OriginPolicy provider is not set.
- Selector text printer: remove support for SS parser subsequent sibling 
  selector hack.
- Update link for W3C DOM level 2 style.
- TokenProducer: add some character constants.
- Remove implementation of CSSUnknownRule, deprecated by W3C and unused.
- Add font-face rule test with additional properties.

 * Dom4j module:
- The insertionIndex logic is no longer used.
- DOM4JUserAgent: connect to resource before opening the InputStream.
- DOM4JUserAgent: small refactor.

 * Java2D module:
- CI test: use a simple network cache.
- CI test: add comparison to DOM wrapper.
- CI test: update Javadoc comment.
- Java2DUserAgent: connect to resource before opening the InputStream, and small
  refactor.