This also removes ascend/descend waypoints. They don't seem to be
helping at all. The AI already gets an implicit ascend waypoint (they
won't go to waypoint one until they've climbed sufficiently), and
forcing unnecessary sharp turns toward the possibly mispredicted ascent
direction can mess with the AI. It's also yet another variable to
contend with when planning hold points, and hold points do essentially
the same thing.
Fixes https://github.com/Khopa/dcs_liberation/issues/352.
21cd764f66