- serial_comm and ftdi_comm features added
- received/recieved typos reverted for inclusion in another PR
- fuel_level change reverted for inclusion in another PR
- DeviceError's 0 field made private again
- allow communication to elm327 device via a serialport
- allow creation of elm327 device without requiring unwrap()
- added some extra documentation
- add fuel_level obd-ii command
- expose reset() functionality of device
