Netdisco

- Include license in source (bachp)
- SSDP: Handle responses without a location (balloob)

- Rewrite discovery to always return a dictionary of found values

Some more things, todo…

- Fix bug where mdns devices would not be discovered.

- Add timeouts to Hue and SSDP requests to make sure that we don't block indefinitely. (balloob)

**This version drops Python 2 support.**
- Fix Hue memory leak (tomusher)
- Hue: properly handle exceptions (molobrakos)
- Extract only max-age from cache-control header (bazwilliams)
- Fix another Hue memory leak (balloob)
- Clean up after we stop scanning (balloob)
- Drop Python 2 support (balloob)
- Remove unnecessary locks (balloob)
- Do not use extra threads for scanning (balloob)

- Revert fluxled (balloob)
- Add NUPNP Hue discovery (grunskis)