Tandem Vehicles

[mayermelhem]

• Added a new method in_tandem() for an alternative constructor for Vehicle() class as many multiple vehicles in tandem (eg. trains, queued vehicles, etc).
• Updated documentation to highlight this and reverse() method for Vehicle() class

Comments welcomed.

[mayermelhem]

Thanks for the feedback.

The motivation is simply a means to create various road vehicle combinations of axle groups (ie. prime mover + multiple tri/quad/quint+ axle groups at different spacings quickly for which then the Envelope augment() method can then be used.

Naturally, the method, which has now been renamed to from_vehicle_sequence() can be extended to looking at trains (locomotive + many carts) or study headways in vehicles.

I have updated the documentation examples demonstrating this for a "superload" case. However, it unsuccessfully ran as per the following raised issue.