+ Added a copy method to the sprite class
+ Added a simple utility class that automatically calculates the colors' components
+ Added a class that resizes Sprites using a scale factor, and a resize method

(Note: For now only nearest neighbor and bilinear interpolation are available)
+ Added documentation
+ Added method for rotating Sprites multiples of 90 degrees
+ Added methods to flip Sprites horizontally and vertically
+ Added a method to rotate a Sprite any arbitrary angle
+ Added a method to add a border inside a sprite
+ Added missing documentation
Merge branch 'feature/ImageUtilities' into develop