[UI] Xcode now properly supports adding custom fonts in storyboard
	removed font logic from table cells and moved to respective scenes in storyboard
changed DHActivityIndicator class to use closure completion handler
finished implementation of VideosTableViewController
implemented infinite scroll in videos
DHNetworkManager now using blocks for succeed and failure upon requests instead of callbacks
cleaned up the DHActivityIndicator class to use solely class methods as it is a utility class and shouldn't be instantiated