TextAnnotation New Model

This change will introduce the following changes to fise:TextAnnotation (and other fise:Enhancements that share the same properties)

• fise:selection-prefix: some words/characters before the selected section.
• fise:selection-head: the first few word/characters of a the selected section within the text. Alternative to fise:selected-text in case bigger sections of the parsed content need to be selected.
• fise:selection-tail: the last few words/characters of a selected section. To be used together with fise:selection-head.
• fise:selection-suffix: some words/characters after the selected section.

The default length of the prefix, head, tail and suffix will be '10'. The length of the selected area where head/tail are used instead of selected-text will be 'max(30,prefixSuffixLength*5)'

This issue covers:

• adaption of the fise.owl file
• adding of the properties to the Properties class
• adding of the setOccurrence(..) helper to the EnhancementEngineHelper: This method will add necessary properties to describe the occurrence within the content based on start, end indexes as well as the content.
• adding support for the new TextAnnotation model to the EnhancementStructureHelper unit test utility.