Several improvements

[sebhoerl]

An (incomplete) list of things that still came to my mind during the last refactoring:

• Define classes such as VirtualNetworkReaderXml, VirtualNetworkReaderBinary, VirtualNetworkWriterX and the same for TravelData in a more object-oriented style like is done in MATSim, e.g. for the NetworkReader/Writer
• Define such readers and writers for ScenarioOptions and LPOptions to make it easier to handle them (not relying on the working directory, etc.)
• Remove SafeConfig, but instead have expressive configuration classes for the dispatchers. There should be, for instance an BasicDispatcherConfig with getters and setters for publishPeriod, rebalancePerid, dispatchPeriod, but dispatchers with more configuration could define classes such as GlobalBipartiteMatchingConfig with additional configuration options if they are necessary.