Add spec for functionality to tokenize inner sentence nodes

- Add spec for tokenizeWord;
- Add spec for tokenizeWhiteSpace;
- Add spec for tokenizePunctuation;
- Add spec for tokenizeText;
- Add spec for tokenizeSource.
Add functionality for tokenizing inner-sentence nodes

- Add tokenizeWord;
- Add tokenizeWhiteSpace;
- Add tokenizePunctuation;
- Add tokenizeText;
- Add tokenizeSource;
- Add private createNode- and createTextNodeFactory methods;
- Refactor classifier to use these methods internally.