refactor(tagsInput): Refactored autocomplete registration

Refactored autocomplete registration in order to expose only what is
needed by the autocomplete directive. In addition, the event system was
normalized and now there's only one way to send events from one directive
to another.
fix(tagsInput): Added event trigger to tryAdd

Changed tryAdd method to trigger an input-changed event after clearing
the input field so the autocomplete directive can hide the suggestions
box properly.

Closes #26.
chore(build): Updated build files [skip ci]