New version 0.9.31

Sorry, a quick update that fixes some bugs that have been really annoying me for a long time:

• Fix landing scenery on planets with traffic-lanes doesn't show lane tiles.
• Fix sometimes visible slight gaps between tiles (e.g. on traffic-lanes) especially in normal (not widescreen) view.
• Fix UI flickering when TAXINAUT is run in full screen exclusive mode under Windows and DirectX. This now is properly fixed and doesn't require the "full screen anti-flicker hack" anymore (which has been removed).
• Manual now has "overview" section (there also a "TAXINAUT Quicktips: Overview" video now: https://youtu.be/3c0HFtAFJVE?si=g6nu6hRPyW5geGqF).