Signature of Predictor::configure must match AnalogComponent::configure,
otherwise the inherited method isn't overridden.
=> predictor couldn't be configured.
=> speed predictor rules in "generic-autopilot-helper.xml" weren't working.
Split the former single-file-implementation in xmlauto.?xx into multiple
files and use some OO techniques. Started with documentation to be used
with doxygen.
