`takeoff|h` does not work as expected with takeoff phases

[eytanadler]

Description

The takeoff|h parameter does set the takeoff and landing altitudes for the BasicMission and MissionWithReserve (though the ground roll in the BasicMission uses its own fltcond|h value). However, the takeoff phase altitudes in the FullMissionAnalysis and FullMissionWithReserve are actually set via each takeoff phases fltcond|h. The takeoff's rotation phase does have an h_initial variable which sets its initial altitude, but then only the obstacle height is connected to the climb phase's initial altitude (not h_initial + obstacle height as you may expect).

We typically leave the takeoff altitude at 0 ft. In this case, everything works as expected, so this does not mean that past cases are wrong. However, future users may adjust this value and they would not get the expected result if they are using the BasicMission with the ground roll phase or either full mission with takeoff phases.