Version 2.4 maintenance release

Focus on fixing some rare case bugs, and improved handling of fleet route constraints.

• Several special cases bugs fixed in fleet router.
• Improved fleet routing with fleet route constraints.
• Fixed a bug that gave wrong times for start and end of a route when dynamic departure was set.
• Added Demand to NodePaths, which is set when the NodePaths is a (partial) result from a fleet route.
• Added ArrivalToEnd property, which gives the time when a vehicle reaches the end node in a NodePath, but before any service time, wait time or driver breaks that are taken on the end node.
• Added FleetRouteFailMessage to Router class, which is set to an explanation if the last fleet route returned null.
• Added OptimizeVIAOrder property to RouteSettings, its default value is true but when set to false the order of VIA points will not be optimized in a VIA route.