An application using multiple I2C devices will need it's own
loop. This reworks the code to make the detection, calibration
constant loading, and measurment functions available too without
having to use the bmp810 task which is still retained.
Adds support for oversampling.
Fixes a bug in the calculation of the temperature.
Better error handling. Checks for I2C errors and errors in the loading
of the calibration constants and propagates these up.
Fixed reference to unknown environment var
Moved drivers into extras folder and added additional documentations.
Changed LOCAL to static and renamed DEBUG to BMP180_DEBUG
