test: coveralls plugin in pom.xml
Rename ProjectState
AppState: move to state package
Dependencies: add commons-io
Config: slight modifications to config classes

- try to use Path instead of String
- Project config now works with project path
- store now works without arguments
ProjectState: class that holds project config and service
ProjectService: reduced implementation to a placeholder
Config: improved configuration classes

- Path information is now stored in the configuration file
Merge pull request #6 from stoewer/project-service

Better configuration file I/O
ProjectService: basic factory method