graphics fix

-fixed the draw function with scaling about an origin flipping the image
in the y direction
removed beeping from the Title screen
(omitted TransferBar test logic)

part of commit "TransferBar fixes, test logic"
Aircraft, Airport scaling

Aircraft:
-now stores and makes use of base_scale, base_speed
+allows it to match the scaling of airports, calculate its own speed
modifier
+stores base speed value for consistency across screen scales
+modifies internal velocity to match scale
-corrected takeoff positionings to be the centre of the runway

Airport:
-now stores scale
+allows it to match game map scaling
+behave consistently across scales (for multiplayer)
-optimised and fixed departures, arrivals, runway positionings

GameWindow:
-passes scale factor on to updated components
-no longer scales aircraft speeds
-isOutOfAirspaceBounds() now honours scale

TransferBar:
-determines internal Aircraft scale depending on available vertical
space
Merge branch 'master' of https://github.com/SEPRGroup/SEPR4Project