Several fixes and new feature allowing grade separated track junctions

Fix an issue where no urban streets are found in a town

Bugfixes and adds in (experimental) support to allow sharing of passenger and cargo tracks

Various fixes including being able to use the AI builder with hand placed stations

Added support for transshipment between ships and trucks and several bug fixes

Various fixes including handling of cargo for modded industries

Adds some highway constructions to allow easier placements and various bugfixes

Bugfixes

Several bugfixes and small improvements

A number of bugfixes, small improvements to the UI