[WEDT-1] Adding support for spell-checking

* What did I?
Add support for spell-checking (detect mistakes and suggest corrections)

* How did I?
Two implementation of SpellChecker interface which allow detect mistakes
and suggest corrections:
- JazzySpellChecker class (use jazzy.jar)
- HunspellSpellChecker class (use hunspell.jar, jna-4.0.0.jar)