GameWindow resizing improvements

-if screen size is small, the altimeter will resize smaller
+drops the altimeter altitude readings from the edges
+leaves more room for the scaling controls
Aircraft documentation update

-updated the constructors comments to reflect older changes
TransferBar fixes, test logic

TransferBar:
-corrected name of bottom right waypoint
-modified update()
+MORE CLOUDS, but less opaque
+optimised feature removal loop in update()
+can now remove more than one feature per update loop
-fixed enterRight()
+now spawns Aircraft heading right -> left

Multiplayer:
-test logic randomly passes flights from the airspace into transfers