Add support for pre-defined routes

[atanisoft]

Currently it is only possible to define turnouts but not routes which consist of multiple turnouts, either DCC or OpenLCB based turnouts.

[TrainzLuvr]

We can already chain LCC events - isn't that creating routes, or do you have something else in mind?

[atanisoft]

This will be more for the DCC side than just OpenLCB event chaining.