Further work on #71 :
- Added config code to fdrs_functions.h.
- Commented all local config settings -> global config settings will be taken by default.
- added a debugConfig function, to check from where settings have been taken. May be moved to a place where sensors and gateways can share code as this is needed only once. For the sake of simplicity the function made it into fdrs_sensor.h and fdrs_functions.h Needs to be refined, as there is redundancy right now.
