Changed validation to only run when text is about to be added.

Note: Doesn't currently work on click. This is due to blur hiding
the suggestion box.

Partially fixes #17
Merge branch 'feature/16-click-add-new' into feature/17-valid-on-add

* feature/16-click-add-new:
  Added ability to click new suggestion and have it added.

Conflicts:
	lib/tokens.js
Added invalid class when validations fails. Defaults to red.

Fixes #17
Allows click to add with invalid message.

Fixes #17
Merge pull request #19 from firstandthird/feature/17-valid-on-add

Feature/17 valid on add