Revert "Remove newlines in HTML comments because it's easier for the extractor that way"

This reverts commit dcaddfaceb043d6e8e1fc53b89a9dccb72bdd767.
Revert "Replace regex-based HTML::CruftText with XML::LibXML based solution" because HTML::CruftText::clearCruftText() has to retain the same line numbers in the output text and XML::LibXML approach doesn't do that

This reverts commit bf903faa5edd4ad16629fbc867e46ce8ad941851.