Fixed javadoc errors/warnings.
Merge branch '2.1-dev' into 3.0-dev

Conflicts:
	src/main/java/org/thymeleaf/templateparser/xmldom/AbstractNonValidatingDOMTemplateParser.java
	src/main/java/org/thymeleaf/templateparser/xmlsax/AbstractNonValidatingSAXTemplateParser.java
	src/main/java/org/thymeleaf/util/DOMUtils.java