Labelling modified

Aircraft:
-removed buffered label images
+changed to draw straight on the canvas provided
+commented to allow reversion if needed
-added speed label
-added Unicode character symbols as labels (arrows)
-bearing code exits in comments; looked cluttered when included
-modified threshholding to complete manoeuvres sooner
-fixed movement bug; now gains altitude correctly with time

Game:
-modified game time calculation to show real time elapsed instead of
time in-game
+calculation is the same, but now independent of game speed changes
+I believe this is in line with the Assmt 2 criteria; ambiguous