* Sensors: refactor configuration
- move sensor implementaion to the .ino,
remove dependency undef / define from sensor files
- update test/build/sensor.h from SENSOR_SUPPORT
- allow to change sensor config variables externally
- `#include <...>` for global headers and libraries,
fix relative path for math library
* add missing sns <-> i2c dependency
* ledrelay should return relay_none as default
* rollback to original test header
* include debug header when requested (relative)
- use similar to relay & wifi, configuration through helper methods that
use indexed defines
- clock cycles for led delay polling
- button mode defaults