* Convert amcrest binary sensors from poll to stream
- Bump amcrest package to 1.6.0.
- For online binary sensor poll camera periodically to test communications in case
configuration & usage results in no other communication to camera.
- Start a separate thread to call camera's event_stream method since it never returns.
- Convert all received events into signals that cause corresponding sensors to update.
- Use camera's generic event_channels_happened method to update sensors at startup,
and whenever camera comes back online after being unavailable.
* Changes per review
* Changes per review 2
* Changes per review 3
- Move event stream decoding to amcrest package.
- Change name of event processing threads so global
counter is no longer required.
- Bump amcrest package to 1.7.0.