Ensure all adapters are unregistered correctly

[JamesLMilner]

I haven't fully checked, but my gut instinct is that the unregister methods for the adapters maybe be out of date/sync with the register methods. We should ensure these are updated to reflect the state of the register methods.

Essentially we need to:

1. Go through each adapter
2. Look at the registered events
3. Ensure there is an equivalent unregister event in the unregister method

[JamesLMilner]

The AdapterListener pattern should have helped with this as now you are forced to call unregister on each listener (i.e. it must be defined). This was introduced in 0.0.15-alpha

Following up on #18 should help make sure this is all handled correctly.