This doesn't add any functionality directly but may open up possibilities
with the other services

This removes BeautifulSoup, gets the requested tags in a different way,
and introduces xmltodict for converting the xml to something useable

This is a fairly large change, but it opens up the possibility of tapping in to
other upnp services that are on the tv. It uses closures to dynamically create
the upnp device methods from the scpd description.

I've tested as much as I can and all functionality seems to be retained.