Upgrade to CSS4J 0.39

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


Version 0.39
------------
 * Core:
- NSAC 1.1 parser configuration extension.
- NSAC implementation: implement NSAC 1.1 parser configuration with STARHACK 
  support.
- NSAC 1.1 rule parsing extension.
- NSAC: add namespace-related parse exception.
- NSAC implementation: throw CSSNamespaceParseException for namespace-related 
  errors.
- NSAC implementation: implement NSAC 1.1 rule parsing extension.
- NSAC implementation: add support for parsing the body of nested rules.
- NSAC implementation: return the CSS2 TR from Parser.getParserVersion()
- NSAC implementation: do not skip comments inside ignorable at-rules.
- NSAC impl.: small correction to CSS test file for additional coverage.
- NSAC impl.: process escaped and quoted values properly in ignorable rules
- CSSOM: if the factory is in LENIENT mode and the parser supports NSAC 1.1, 
  enable STARHACK.
- CSSOM: Refactor introducing the CSSDeclarationRule interface.
- CSSOM: normalize name for CSSSupportsRule constant.
- CSSOM: extract a few W3C interfaces from at-rule implementations.
- CSSOM: refactor, introducing the ExtendedCSSRule interface.
- CSSOM: tests for rule's clone(sheet) method, with fix for OMCSSPageRule
- CSSOM: refactor related to declaration-specific SAC DocumentHandlers.
- CSSOM: add support for several at-rules.
- CSSOM: refactor of @supports rule implementation.
- CSSOM: add numbers for new rules, and small visibility adjustments.
- Add several at-rule factory methods to ExtendedCSSStyleSheet.
- CSSRuleArrayList: supply an 'appendRule' method instead of just 'add'.
- OMCSSNamespaceRule: add a setPrefix() method allowing to change prefix.
- BaseCSSStyleSheet: throw DOMException of NAMESPACE_ERR type when 
  CSSNamespaceParseException is found.
- OMCSSPageRule: set and get the page selector according to spec methods.
- Revert "Remove implementation of CSSUnknownRule, deprecated by W3C and 
  unused."
- Instantiate a CSSUnknownRule for unsupported SAC 'ignorable' rules.
- Sheet error handler: add a method to report fatal issues with at-rules.
- SheetErrorHandler: new arguments for non-style at-rule error reporting.
- Do not include semicolon for last longhand in minified declarations.
- Rename package doc.html to doc.dom.
- Add SPDX header. See https://spdx.org/using-spdx
- Improved licensing header for NSAC files, including SPDX identifier.
- New licensing header for W3C files, and relevant LICENSES.txt file.
- Add the 'final' modifier to several fields (and make some 'private').
- Fix a few Java 9 newInstance() warnings
- Remove BOM mark from sample css used in tests
- Add a few tests for DOM wrapper.
- DeclarationParserTest: add a unit test and rearrange some lines.
- CSSIdentifierValueTest: additional test.
- BaseCSSStyleDeclarationTest: additional test.
- BaseCSSStyleSheet: add a comment.
- OMCSSGroupingRule: small Javadoc corrections.
- Update copyright notices to 2018.

 * Dom4j module:
- Adapt to refactors in core module.
- Add SPDX header. See https://spdx.org/using-spdx
- Fix a newInstance Java 9 warning
- Update unit test to account for CSSUnknownRule support.
- Update copyright notices to 2018.

 * Agent module:
- Add SPDX header. See https://spdx.org/using-spdx

 * Visual module (staging):
- Package doc.html in core renamed to doc.dom.
- Add SPDX header. See https://spdx.org/using-spdx
- LICENSE.txt: Update copyright notice to 2018.

 * Java2D module:
- Package doc.html in core, renamed to doc.dom.
- Add SPDX header. See https://spdx.org/using-spdx
- LICENSE.txt: Update copyright notice to 2018.