# Functions
NewColourButton creates a new ColourButton of the specified colour.
NewImageFileButton creates a new ImageFileButton with the specified image on it.
NewTextButton creates a new TextButton with the specified text on it, in white on a black background.
NewTextButtonWithColours creates a new TextButton with the specified text on it, in the specified text and background colours.
# Structs
ColourButton represents a button which is a solid block of a single colour.
ImageFileButton represents a button with an image on it, where the image is loaded from a file.
TextButton represents a button with text on it.