(optional) use of a pressure sensor to get (more precise) altitude
Send altitude from pressure sensor quickly
Altitude: above sea level instead of above the WGS84 reference ellipsoid

Use Nmea to get the height of geoid above WGS84 ellipsoid

* http://stackoverflow.com/questions/9361870/android-how-to-get-accurate-altitude?rq=1
* http://aprs.gids.nl/nmea/#gga
Settings: pressure sensor & altitude correction
Use geoidHeight if we already got one
Title WGS84
Change geoidHeight => recalibrate altitude2 (pressure)
Merge pull request #13 from jay3/1.4_Pressure_Altimeter

Altimeter using pressure sensor and WGS84 altitude correction