Corrected PKView properties (details below)

- Delegates should _always_ (ALWAYS) be weak.

- Made properties readonly should should be (mutation of these would have been
  unsafe, so let's be honest.)
Don't add someone else's delegate methods to your own interface
It's not polite to steal first responder status without asking

Initializing the component shouldn't just cause it to become first responder.
How infuriating if you have other fields you wish to come before this one.