Trap for null slices in find_nearest_slice
Initial Climb phase amended to cater for climbs that do not reach 1000ft.
Also, Initial Climb flight phase test added and helper build_kti added.
Removed reference to noisy signals.
Climb Acceleration Start - trap for cases where the aircraft does not reach a normal acceleration altitude.
Merge branch 'master' of https://github.com/FlightDataServices/FlightDataAnalyzer