OSD and telemetry output of vario data is enabled on F4 and up targets
that have
USE_BARO defined. Settings and telem elements are removed from all
other targets.
F3 targets are not supported to free memory.
Harmonized (and partly corrected) all occurancies of gpsSol.llh.alt and getEstimatedAltitude() to handle altiude sourced in cm resolution.
This was introduced by GSP_RESCUE/RTH.
Introduced a naming convention that include the unit into the variable/function names:
gpsSol.llh.alt -> gpsSol.llh.alt_cm
getEstimatedAltitude() -> getEstimatedAltitude_cm()
