Fixes #1740 - not tested on hardware
MEGA2560 update
Fixes #1630 - Thanks to projectkk2glider for his pull request #1738 - I
only added a google test
mega2560 RotaryB ok
RotaryA ok

Interrupts 0 and 1 changed to 4 and 5
Fixes #1657:
* corrected varioLimitCenterMin range
* removed varioLimitMinOff checkbox (it is not used anymore in any radio)
Re #1696: fixed incorrect display of "<" and ">" characters
Warning removed
Merge pull request #1751 from opentx/projectkk2glider/issue_1657_vario_limits

Fixes #1657:
Conversions shift fixed
New trainer modes:
- Master / SBUS module
- Master / CPPM module
- Master / SBUS in battery compartment
Thanks to Mike for this feature!
Master/SBUS Module now working
Now SBUS / Battery compartment works!
Translations updated
New trainer modes added in Companion
Merge pull request #1753 from opentx/bsongis/New_trainer_modes

Bsongis/new trainer modes
Telemetry refactoring start ... Only S.PORT for now. Sensors discovered
automatically. Still a lot missing.
Fix default precisions
Delete telemetry sensor wasn't stored
Telemetry refactoring continued