Implemented the data model and drawing of rectangular hitboxes, IsometricCoordsConverter functions have been transferred to Hitbox class as static, since they are generally needed for hitboxes only

src/repository/Project.java

@@ -190,6 +190,7 @@ public class Project implements Iterable<Entity>, EntityDrawboxChangedListener {
 			if (!imageFile.exists())
 				throw new FileNotFoundException();
 			BufferedImage image = ImageIO.read(imageFile);
+			
 			return image;
 		} catch (FileNotFoundException fe) {
 			logger.warning("Image file \""+path+name+'.'+extension+"\" is not found!");