Miles are bigger than kilometers

Dependencies

• [2] TZVTKOJE Use named variables for planetary radius
• [3] E742MTJA Fix segfault (don't pass pointers between functions in different SDL versions), minor refactor
• [*] ROQCAPZJ Begin function for showing the map (for now just opens SDL window)

Change contents

• replacement in trainmodel/src/drawmap.py at line 12
  [2.27]→[2.27:76](∅→∅)
  − planet_radius_miles = planet_radius_km * 1.60934
  [2.27]

  [3.87]
  + planet_radius_miles = planet_radius_km / 1.60934