FlightMenu labelling, refactoring, fixes; misc

Airspace:
-removed score console spam

FlightMenu:
-added labels to buttons, scales
+changed button size to accomodate "Take Off"
+!still uses constant values for speed labels
-refactored altPos value to be more maintainable
+no longer stored -sliderWidth offset
+can use value as originally intended for relative calculations
+needs explicit offset only for rendering off altBase
-corrected speedBase rescaling calculation to use speedSize