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Merge remote-tracking branch 'origin/target-4.4.2' into target-4.4.2
fix bug not handling scanMode -y for MSGnavigation;
review scanMode, may need further work;
add unit tests for scanMode;
Eumetsat correction for MSGnavigation needs to be specific to center 254
Merge remote-tracking branch 'origin/target-4.4.2' into target-4.4.2