Gear Extending, Extended, Retracting and Retracted methods re-written and test cases improved to reflect issues with real data.
Retracted and Extended repair the array for large chunks (and extrapolate) so that the phases get extended to the ends of the data as required.

Gear (*) Red Warning created to save creating it 3 times over again.
Gear (*) Red Warning commit - missed from previous, oops
nearest_neighbour_mask_repair now takes a limit to ensure it doesn't roll repair forever - which is very time consuming.
ILS Localizer Established optimisation - ILS Frequency only repaired for approach sections. Improvement also that long gaps between frequencies are not filled to avoid scanning data where ILS is not established for prolonged periods. A bit of logging added too.
KPV tidy up
step_values fix for when value nor rate of turn method return a value
merged and conflict in library.step_values resolved