Probably a bug in SliderLayout.getCurrentSlider().

Hello there,
First of all i really want to thank you for this gorgeous library, and the amazing documentation that you put together.

I noticed that if you call the method SliderLayout.getCurrentSlider() without any Slider in the SliderLayout you get "a divided by zero" exception. I don't know if this is an intended behavior or not.

If it isn't an intended behavior can i suggest that the method returns null, or the method should specify that it may throw a divided by zero exception in case it got called before filling the sliderLayout.

Also an other thing, can you add a function to determine if the SliderLayout is empty?

it may look something like this:

SliderAdapter.isEmpty(){
return mImageContents.size() == 0;
}

SliderLayout.isEmpty(){
return mSliderAdapter.isEmpty();
}

again Thank you so so much for this amazing library and i apologize if i'm not using github right, this is my first using github.