Add triangle position, type and size customization options

This doesn't work for me, the triangle's frame Y value is incorrect, and works better with the following:
```objc
triangleFrame = CGRectMake(self.view.frame.size.width/2-(self.triangleSize.width/2), nextYPosition + self.titleScrollerHeight - self.triangleSize.height, self.triangleSize.width, self.triangleSize.height);
```