Enable customizing the user interface of the image viewer

[jesster2k10]

I created a global class called EBConfig that allows developers to change different features of the user interface easily e.g font, font color, date formatting etc.

I also added a feature to load the comment avatars from a NSURL opposed to a UIImage incase there is networking involved. Feel free to change anything, I just had to change a few things to work for my project.