Add height to GPS data.
Merge branch 'master' of https://github.com/thauta/ruuvitracker_fw
Get rid of gps_data.ew and gps_data.ns.
GPS: replace height with altitude.
GPS: report vdop as vertical_accuracy and hdop as accuracy. Update tracker script to send more data.
GPS: remove gps_set_power_state().
GPS: report the latest number of satellites in view, not the previous. Expose pdop as positional_accuracy to lua.
Merge pull request #21 from thauta/master

gps lua api updates. example_tracker updated to use new api.