-Codechange: Move SmallMapWindow declaration to header and unindent implementation
-Codechange: refactor smallmap some more to allow for easier addition of new map type
-Codechange: make NWidgetSmallmapDisplay a friend of SmallMapWindow and then make a whole lot of members of SmallMapWindow protected
-Codechange: Introduce save/load version naming
-Feature: record capacities of links
-Add: basic linkgraph
-Add: demand calculation for linkgraph
-Add: MCF solver for linkgraph
-Add: flow mapper for linkgraph
-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
-Feature: linkgraph overlay for smallmap
-Feature: consider cargo waiting at other stations for rating at the origin station
-Feature: show cargo by next hops and final destinations in the station GUI
-Codechange: remove STR_STATION_VIEW_CARGO_RATINGS_TITLE
-Add: help texts for settings
-Add: german translation