[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
[update] visualization use the new YamlReader Writer
[delete] the old YamlPersister from common
[add] new junit-tests for Yaml and Properties
[delete] old junit test for PropertiesReaderWriter
[update] move new Properties classes in new package