- IAnnotationValueProvider

 - add setAnnotationValue(String value, T specification) in addition to setAnnotationValue(V value, T specification) variant
 - This enables to use the String-based AnnotationEditingSupportStandard for non-String annotations.
 - Concrete AnnotationValueProviders must implement this method and convert the String representation of the input to the storage format provided by the respective annotation class (e.g., for Double, just by using the Double(String) constructor)
 - The current implementation  has been tested with String, Double, enum and multiple value String annotations

- TODO:
  - Cleanup of IAnnotationValueProvider
  - Base class hierarchy for common concrete annotation value providers
  - multiple value annotation support in GenericAnnotationView