Use Parameters in Launch file

[lorixhack]

Features

• pass a config file from command line or use a default one
• geometric constants and EnEA values have been moved in the config file from constants.py
• two more config files (one for mk1 with vcan0 and one for mk2 with vcan0)
• each node receives the relevant parameters (obtained from the parsed config file), which have been declare as launch arguments
• modifications in each node in the use of the parameters
• launching EnEA conditionally to the version (only if is mk1)