Remove `api` tag from docblocks in custom crawler

Kids, you should always be careful when copy-pasting stuff.
Add K/Dossier/HtmlToXmlConverter

This converter takes the HTML source of the complete page of a dossier and transforms it to an XML tree, thus making it easier to work with.
Add K/Dossier/XmlToArrayConverter

This converter takes an XML tree of the complete page of a dossier and transforms it to a native array-based PHP structure.