feat(typeahead): Added -auto-highlight & -prevent-submission options

Proposition for issues #908 and #1298

- Added typeahead-auto-highlight option (default to true, meaning the first matching item is automatically activated)
- Added typeahead-prevent-submission option for preventing or allowing default enter event on input field (default to true meaning form won't be submitted if control is in a form)
- Improved key events handling for better UX (Setting autoHighlight to false causes popup to have no item selected at first and changes the way some events are handled)

Unit tests will follow in the next few days