Upgrade to CSS4J 0.38

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

Version 0.38
------------
 * Core:
- Change the default parser to this library's own NSAC implementation.
- Move classes in doc.style.css.dom to new package doc.style.css.om.
- NSAC implementation: ignore media rules with invalid media specs.
- NSAC implementation: when creating an identifier unit for 'unset' or 
  'initial', convert to lowercase.
- NSAC implementation: add test for pseudo-classed pseudo-element.
- New interface CSSRatioValue.
- Support ratios in media queries.
- Accept css-wide keywords in more shorthands including background, transition,
  border-width, border-style and border-color.
- getPropertyValue/getPropertyCSSValue: convert property name to ASCII lower 
  case only if it is not a custom property like '--foo-color', per 
  https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-getpropertyvalue
- CSSStyleDeclaration.setProperty: convert property name to ASCII lower case if 
  it is not a custom property, per 
  https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-setproperty
- CSSStyleDeclaration.removeProperty: convert property name to ASCII lower case 
  if it is not a custom property, per 
  https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-removeproperty
- CSSStyleDeclaration.setProperty(String, String, String): if value is the 
  empty string, invoke removeProperty() with property as argument per 
  https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-setproperty
- Add getUserAgentStyleSheet() method to CSSStyleSheetFactory.
- CSSStyleSheetFactory: add a style sheet argument when creating a 
  SheetErrorHandler.
- Add method unexpectedProperty to SheetErrorHandler.
- DOM implementation: add a toString() to node lists.
- DOM implementation and DOM wrapper: remove non-CSS <link> elements from the 
  link collection.
- Adjustments to ValueFactory: support custom calc values and prevent one type
  of bugs.
- Fix a serious bug introduced in 0.31: a comment inside a style declaration 
  would invalidate the rule.
- Fix bug in CSS DocumentHandler: an 'and' in a media check should be an 'or'.
- Fix: media queries can be empty.
- Bug: integer primitive values did not opt-in for complex (list) values.
- Try to fix a memory-footprint regression introduced in 0.37.
- CSSOM: clean up the possible references to SAC lexical units that are no 
  longer needed.
- Remove an unnecessary cast from AbstractStyleDatabase.
- SS Cssparser no longer uses the subsequent sibling selector hack.
- DefaultStyleDeclarationErrorHandler: report unassigned shorthand values.
- Minor correction to SAC parser instantiation logging.
- Documentation: add a description to the CSSElement and SelectorMatcher 
  interfaces

 * Dom4j module:
- Package doc.style.css.dom was renamed to doc.style.css.om.
- Implement getUserAgentStyleSheet() in the style sheet factory (it was already 
  in the document factory).
- Compare to a lowercased String instead of an equalsIgnoreCase when evaluating 
  the rel attribute in linked styles.
- Remove specialized element classes that were defining default styles at the 
  wrong place.

 * Agent module:
- Package doc.style.css.dom was renamed to doc.style.css.om.
- DefaultOriginPolicy: add two missing Override annotations.

 * Visual module (staging):
- Package doc.style.css.dom was renamed to doc.style.css.om.

 * Java2D module:
- Package doc.style.css.dom was renamed to doc.style.css.om.
- Add test-jar production to Maven POM.
- CI tool: more informative messages for some error cases.