Data Initializer for sampleapp

Fixes #53

Proposed Changes

Mixin for Dactors (called DataInitializer) handling loading data from CSVs into the internal relations
Mixin DefaultMessageHandling instead of overwriting unhandled in Dactor
Dactor responsible for system startup and loading our testsdata --> SystemInitializer
Manifest data in resources folder
let all sampleapp dactors support data initializing and default message handling
addition to CSVParser:
- ability to process java.io.Streams
- use these streams in DataInitializer
- getClass.getResourceAsStream(name): InputStream does also work for resources inside jars, whereas getClass.getResource(name): File does not!