These correspond to versions from v2.1.108 and v2.1.147.
The oil rig airport type bug is fixed as of version 221.
The oil rig type has been moved, but this is not a problem as
the afterload code already remaps it to the correct value.
The cost scaling issue also seems to have been mostly fixed
as of version 221.
Huge airports are not supported.
Annoyingly SpringPP has a bug where it uses the same ID for
AT_INTERCONTINENTAL2 and AT_OILRIG.
Consequently any aircraft approaching an oil rig in an SPP game
will be using the wrong aircraft movement data, and this will go
badly wrong as soon as the game is unpaused.
This is useful for loading settings from legacy/special versions,
where the corresponding setting is somewhere else and/or a PATX setting,
with duplicating all the info.
Use this to load SpringPP settings which have a corresponding setting.
No longer set vehicle lateness to 0 if separation fails, instead
leave it as it was.
The setting defaults to 100% (full abruptness, old behaviour).
Reduce the setting if auto separation is too disruptive, e.g. causes
excessive waiting in stations.
Note that this is not savegame compatible.
This is to prevent positive feedback where timetable times are increased
due to congestion, which creates more congestion due to trains waiting
for extended periods at stations and/or due to timetable auto separation
going overboard due to overly long timetables.
* Double rate of negative adjustments.
* Half rate of positive adjustments.
* Only do step changes for large negative adjustments.
* Reduce jam detection threshold.
This is an exponentially weighted moving average of occupancies updated
when any vehicle in the shared order set leaves the station of that order.
The weighting factor is an adv setting.
SpringPP divides all prices by the difficulty factor, effectively making
things about 8 times cheaper. Adjust the inflation factor to compensate
for this, as otherwise the game is unplayable on load if inflation has
been running for a while. To avoid making things too cheap, clamp the
price inflation factor to no lower than the payment inflation factor.
Savegame version 220
Bin all extra settings added in SpringPP.
Bin extra features: trip histories, more conditional orders/jump counter,
prev order time, snow-line chunk, town auto adv. campaign, etc.
Fix vehicle flags.
Fix bridges wrt height changes.
Handle 60-bit RIFF chunk sizes.
Doesn't deal with huge airports, loading games with these may
lead to undefined ehaviour.
PAX signals and traffic lights are ignored.
