Tvguide fix

This tvguide-fix branch fixes the tvguide parsing and converts the module into a plugin/class

The TVGuide XML parsing is fixed by rewriting it to use XmlDocument DOM-like parsing

Most coding was done already some time ago but after that I lost focus on it, so I can not say that with this TVGuide is completely working. What I saw is that the XML parsing was not working before and that with this patch it was working for me so while it may not be a final fix, it is an improvement I think.