-Codechange: Introduce save/load version naming
-Codechange: Signature of CargoList::Truncate in preparation for unification of cargo movement methods
-Codechange: some internals of cargo packets and lists in preparation for unification of cargo movement actions
-Add: general framework of cargo actions
-Codechange: make cargo reservations persistent.
-Feature: show reservations in station gui
-Feature: record capacities of links
-Add: basic linkgraph
-Add: demand calculation for linkgraph
-Add: MCF solver for linkgraph
-Add: flow mapper for linkgraph
-Feature: allow vehicle transfer and profit text effects to be displayed at the same time
-Add: multimap implementation with guaranteed order between equal keys
-Feature: distribute cargo according to plan given by linkgraph
-Add: abstract implementation of linkgraph overlay for GUI
-Add: legend for linkgraph overlay
-Add: linkgraph overlay over main viewport
-Codechange: refactor the smallmap to prepare for linkgraph overlay
-Feature: linkgraph overlay for smallmap
-Feature: consider cargo waiting at other stations for rating at the origin station