Implement handleEvent

[AutoSponge]

• addresses Event Failures #99
• Fixes failing tests

Needs discussion and possibly further tests. Designed to build components. Any copy features built based on bel will likely want to copy el.events from element to element rather than their current implementation so this is likely a breaking change.

There's an alternate implementation that looks like this:

        el.events = el.events || {}
        el.handleEvent = dispatch
        el.events[type] = val
        el.addEventListener(type, el)

In this case, the listener points to the el and dispatch looks for the events object property. This may be a better pattern since it's easier for the implementer to overwrite handleEvent at the element level. When copying events, you can iterate over Object.keys(events).

It may be worse because when copying events between elements, you need to copy the events expando property and also add handleEvent instead of it all coming in the same package. You just have to remember skip handleEvent when iterating the events object.