Storyboard

Hi,

I found your custom view nice,  and I'm going to use it in a my project.
However, for my application I need additional features, such as  display the integral amount of the task that has completed instead of its percentage, as well as draw the custom view in the storyboard.

So I developed these features and now I'd like to share them with you.
I kept backward compatibility with your code when the ADVPercentProgressBar class is instantiated programmatically.
I also added some documentation.

Thank you.
Corrado