colorhug: Use a different PID for the ColorHug2 bootloader

The devices have different configs as the clocks are different.
colorhug: Use the calibration capability to be able to do a unity measurement
colorhug: Add ch_device_mode_from_firmware()

This allows us to look for known tokens in the binary firmware file.
colorhug: Add ch_device_check_firmware()

This returns an error if the firmware binary data is invalid.
Release colord 1.2.3