Release 0.9: faster communication over USB

- Configurable communication delay when transmitting responses over USB, defaults to 75 µs. This was previously 2
ms (default value of hardware), now communication takes 2 ms less time
- Added libusb_package dependency, required for configuring the communication delay
- ECUManager now skips already open serial ports by default, this allows several instances of the ECUManager to be
used across different Python programs at the same time
- ECUManager now supports excluding serial ports from being scanned
- Fixed `calibration_to_file` not saving calibration values
- Fixed typo in `enabled_all` method
- Report UUID and product ID of unidentifiable ECU hardware
- Added DIGITALINPUT command
- Only reset serial port read buffer when communication fails, this speeds up communication
- Started implementing CP2102N (USB-Serial chip used in ECUs) with pyusb without requiring the proprietary SiLabs
VCP driver
- Added MIT license information to source files