General code tidy up

- access modifiers adjusted
- unused declarations removed
- spelling fixes
- removed redundant code

visualiser/src/main/java/seng302/Model/ResizableCanvas.java

@@ -7,7 +7,7 @@ import javafx.scene.canvas.GraphicsContext;
  * Created by fwy13 on 4/05/17.
  */
 public abstract class ResizableCanvas extends Canvas {
-    protected GraphicsContext gc;
+    protected final GraphicsContext gc;
 
     public ResizableCanvas(){
         this.gc = this.getGraphicsContext2D();