Simplify follow_track.hpp.
Separate an assertion.
Detect hangars in IsDepotTypeTile.
Simplify and document GetOrderCmdFromTile.
Clarify vehicle_enter_track in rail_cmd.
Simplify CheckTrainStayInDepot().
Do not track *.rej, *.orig and kate garbage.
Saveload versions, for easier merging.
Add settings for group hierarchy.
Add function for "Group inherits properties from parent".
Always set INVALID_GROUP as parent for a newly created group.
Revert hierarchical groups in GUI. Need to sort out how to deal with them.
GetGroupNumEngines depends on setting for group statistics.
Modify alter command. Add default names and other changes.
SetGroupReplaceprotection uses group hierarchy settings.
Add an assert at compile time for saveload version.
Small codechange for opening terraforming window.
Position of landscaping toolbar.
Landscaping dropdown doesn't need trees and place signs entries.
Change CmdAddSharedVehicleGroup so the command is called less times.