V3.9: Updated wake turbulence categories and minor adjustments — Endless ATC Steam update #859614

A small update with more wake turbulence categories, graphical adjustments, and bugfixes. Patch notes: Added three more wake categories, totalling 6 (like RECAT in real life, which is used at several big airports). It isn't really noticable when playing (heavy and superheavy are still labeled H and J) but it's less strict for some combinations of planes, so it allows for more efficient wake vortex separation; fewer go arounds. The heavies and mediums are basically split up into subclasses. This system also allows for less time between departures: better flow rates! Wake arc on the localizer will now adapt dynamically to the required distance between two plane categories (instead of displaying two arcs for H and M categories, now only one arc is displayed at the required distance). Planes inbound secondary airports have a slightly different label color, so they're easier to distinguish fr...