improved orbiting objects' orbits, especially how the energy is checked (for breakup), and angular momentum handling

improved how objects are unbound (new ORBITING_OBJECT_TYPE_UNBOUND) so they can be followed even after

added a new post_events_sync function that is used when there's an event to update the system's orbit.

abstract out the wind orbital angular momentum derivative to its own function so this can be called by the orbiting object code

added angular momentum derivatives to orbiting objects