Pykarbon

+ Catch attribute error in Interface.release()
+ Override can.autobaud when using pykarbon.Karbon

+ Separate main hardware tools and Karbon class.

+ Add actual base tool tests
+ Add canbus tests
+ Have baudrate set to None on failure to detect

+ Add change log
+ Update __all__ to include terminal.py
+ Turn base Karbon read/write into context managers.
+ Better formatting of terminal configuration lines.
+ Print error messages when terminal command fails.
+ Fix update_firmware.py.