Refactor tours as a named parameter to solve methods.
Added mode to choose from a set of candidate destinations.
Arguments following the new --route-set switch form a list of destinations from which we should choose only one (or the number specified by --route-set-min and/or --route-set-max) to add to the route.
As an example, suppose you were planning to travel from Alacarakmo to Wuthielo Ku and wanted to collect some rare goods along the way. To choose from a list of candidate systems you could run the following: