Enegry label parsing should be much simpler and faster now...

* Vastly simplified the parsing of energylabel data (using the new module XML_STREAM).
* Also using the new module DCG_DATE for date parsing.
* Use threads for adding newlines in XML files. Also more efficient processing. From hours to minutes! A quite heavy memory profile though. Why would that be?
* Use XML_TO_RDF from the XML2RDF conversion now. This needs some work...