Apply averaging to pressure measurement: In pre versions calculated pressure value jittered +/-10hPa. Since we measure the pressure several time a second but only use one value a second, calc average including not used values Activated pressure / temperature offsets: The functionality to store offsets was already present in the firmware but values have not been apllied in the RTE => added functionality to include offsets in calculation Set Max possible surface pressure to 1070hPa (Black sea level)

Imported from Ac6/SystemWorkbench/plugins/fr.ac6.mcu.firmware_1.14.7.201711101414/resources/builtin/:
* File syscalls.c