Async-upnp-client

- Add SSDPListener which is now the underlying code path for async_search and can be used as a long running listener (bdraco)

- Add UpnpFactory non_strict option, replacing disable_state_variable_validation and disable_unknown_out_argument_error
- UpnpAction tries non-versioned service type (68) in non-strict mode
- Strip spaces, line endings and null characters before parsing XML (apal0934)
- Properly parse and return subscription timeout
- More strip spaces, line engines and null characters before parsing XML

- Improve performance of parsing headers by switching to aiohttp.http_parser.HeadersParser (bdraco)

- Don't double-unescape action responses (50)
- Add ``UpnpDevice.service_id()`` to get service by service_id. (bazwilliams)
- Fix 'was never awaited'-warning

- Fix timespan formatting for content > 1h
- Try to fix invalid device encodings
- Rename ``async_upnp_client.traffic`` logger to ``async_upnp_client.traffic.upnp`` and add ``async_upnp_client.traffic.ssdp`` logger
- Added ``DeviceUpdater`` to support updating the ``UpnpDevice`` inline on changes to ``BOOTID.UPNP.ORG``/``CONFIGID.UPNP.ORG``/``LOCATION``
- Added support for PAUSED_PLAYBACK state (56, brgerig)
- Add ``DmrDevice.transport_state``, deprecate ``DmrDevice.state``
- Ignore prefix/namespace in DLNA-Events for better compatibility
- DLNA set_transport_uri: Allow supplying own meta_data (e.g. received from a content directory)
- DLNA set_transport_uri: Backwards incompatible change: Only media_uri and media_title are required.
To override mime_type, upnp_class or dlna_features create meta_data via construct_play_media_metadata()

- Added ability to set additional HTTP headers (51)
- Nicer error message on invalid Action Argument
- Store raw received argument value (50)
- Be less strict about didl-lite
- Allow targeted announces (53, elupus)
- Support ipv6 search and advertisements (54, elupus)