Upnp for 4.0.0

Extended UPNP support updated and integrated into the web interface, featuring new browser-to-upnp playback and playlist mgmt.

Reminder: although renderer recognition should work as-is, there's a new faster  ```UpnpDetailsSearch``` renderer conf setting which is made up of any snippets of text copied (in the same order) from the upnp details on the renderer panel, separated by " , ", e.g.
```
UpnpDetailsSearch = <manufacturer> , <modelName>
```