Trigger actions for UIControlEventPrimaryActionTriggered upon touch up inside

[natanrolnik]

Recently, I've came accross the (not so) new UIControl.Event.primaryActionTriggered available since iOS 9.

Although the documentation I could find doesn't describe enough about it, this book says the following:

Starting in iOS 9, a control also has a primary control event, a UIControlEvent called .primaryActionTriggered. The primary control event is Value Changed for all controls except for UIButton, where it is Touch Up Inside, and UITextField, where it is Did End On Exit.

I believe that TORoundedButton should behave like a UIButton, and this PR adds this subtle change. It hooks up on the .touchUpInside action to fire the actions registered on .primaryActionTriggered. Although I couldn't find a way for a UIControl subclass to override/change the primary action, this solution adds this capability to TORoundedButton.

[TimOliver]

Oh nice! I had no idea that existed! Thanks a lot! :)