* Partial support for some Nano receivers.
* Improved support for some devices: M510, K800, Performance MX.
* Improved battery support for some HID++ 1.0 devices.
* Properly handle device loss on computer sleep/wake.
* Better handling of receiver adding and removal at runtime.
* Removed a few more unhelpful notifications.
* Incipient support for multiple connected receivers.
* More Python 3 fixes.