- [add] new yaml-Properties, reader and writer class
- [add] new hierarchic dataservice_config yml-file
- [add] property key-Path function
[add] - PropertyExcetion class
          - set(String,Object) method
[add] - Java-Doc and exception handling to Properties class
[bugfix]   connection too much
[update] use Properties class in dataservice
[update] delete unused code from dataservice
[update] removed old properties config file from dataservice
[update] switch new Property classes to common
[update] adding new get methods for defaultValue
[bugfix] no longer overwrites existing keys
[update] the new Properties class use by visualization
[update] old property files removed
[update] unused code removed
[update] change loglevel from debug to trace
[update] get methods return now the requested data type back. Regardless what is in the config.
[fix] Java-Doc @return
[update] now is the set method recursive
[add] new YamlReader and Writer
[update] PropertiesReader and Writer use new YamlReader and Writer
[update] change all throwable Exceptions to PropertyException
[update] Dataservice use the new YamlReader and Writer