title: UIView subclasses default properties
body: <p>What's the proper way to set a default value for a UIView subclass's property?</p>
  
  <p>Although I'm not using them yet, if the XIB provides a value I'd like it to override the default. But if the XIB doesn't provide a value, I'd like my default value.</p>
  
  <p>In this case, I'm thinking of a CGFloat value specifically. While it could be set to 0.0 this isn't a useful default, so checking for a value of 0.0 in my code and replacing it with a better value is something I'd rather avoid.</p>