Allow custom events with '.' in the name

[MichaelRFairhurst]

We restrict '.'s to only keyup/down events (see #423).

However, raised in #423 by @zoechi is a great point, that users can fire custom events of any name including '.'s. To support this, we should sync with the angular project itself to ensure they'll be able to handle it, and we should implement it on our side much like #454