Python-socketio

- Do not allow event names with hyphens in them [36](https://github.com/miguelgrinberg/python-socketio/issues/36) ([commit](https://github.com/miguelgrinberg/python-socketio/commit/a6838a233d051b406baeb9a4c09e50f62bc9f14a))
- add unit test for sleep function ([commit](https://github.com/miguelgrinberg/python-socketio/commit/a3ae2a938472f103d543ad46ff6d923c0f2415ee))

- fix the order of triggered disconnect event [33](https://github.com/miguelgrinberg/python-socketio/issues/33) ([commit](https://github.com/miguelgrinberg/python-socketio/commit/ea1a52ac84cf2cd3d5cb6d1c0f6a64932159d835)) (thanks **Hanzawa Ye**!)
- Correct sio.emit() call in readme [32](https://github.com/miguelgrinberg/python-socketio/issues/32) ([commit](https://github.com/miguelgrinberg/python-socketio/commit/a1ca2c421c4f2f05e83372e4dac0b3826be66d16)) (thanks **winek**!)

- pass return value of start_background_task to the caller ([commit](https://github.com/miguelgrinberg/python-socketio/commit/cd9e1a7c6427eb6e13abea15d84dfc692f843df2))
- a few improvements to examples ([commit](https://github.com/miguelgrinberg/python-socketio/commit/0810f0b039753d9c98f83eebf5a1b183aabd6d49))

- a few improvements to examples ([commit](https://github.com/miguelgrinberg/python-socketio/commit/20185c9a95bcd1ab4d4457b483cf6172eaf020c2))
- expose async_mode and sleep from engineio ([commit](https://github.com/miguelgrinberg/python-socketio/commit/065cc4b2219d22f7b470600073f21c47c09d5578))

- delay start of message queue listener thread until first request comes ([commit](https://github.com/miguelgrinberg/python-socketio/commit/b6df63d8492c9a18e7d4a7ea5e8378e076b7a723))
- Avoid KeyError when no room exists [27](https://github.com/miguelgrinberg/python-socketio/issues/27) ([commit](https://github.com/miguelgrinberg/python-socketio/commit/626499cd4596c13a41a5ecbe3e350b243c5fe6be)) (thanks **Patrick Decat**!)

- Avoid KeyError in is_connected. [22](https://github.com/miguelgrinberg/python-socketio/issues/22) ([commit](https://github.com/miguelgrinberg/python-socketio/commit/cba6c3ed8b8b2c777538a5a35e73f98f4ec9d4bb)) (thanks **Chris Doehring**!)