Android/I2CBaroDevice and NunchuckDevice: add missing gcc_override.
Android/I2CBaroDevice: Use SetAccelerationVariance to set kalman properties.
Android/I2CBaroDevice: Use unfiltered static pressure value for ProvideStaticPressure() and airspeed computation.
manual.mk: Prepared manual build for a German translation,
added the path to the English version as last default to avoid copies for not jet translated file.
Manual: Reworked icons for config reference, gesture, and tip now in svg format.
Manual: Put new margin icons in xc manual style and deleted the replaced icon files.
Manual: Warning sign in same style as other margin symbols.