Crash fixed

• Fixed a crash which took several days to find, it was from portal object being saved to Entity as b2Body* but later accessed as Portal* which should have been obvious, it was a change I made a long time ago
  • To find the crash I had originally tried to use reverse debugging from Ubuntu which I couldn't get to work
• Stencil rendering fixed for portals since new nanovg vector graphics rendering for shapes was put in place (regression fix)
• Ready to work on training DRL (deep reinforcement learning) dark noform assuming multiplayer and logistics problems are solved for the DRL episodes to go smoothly. Then I can use the base model and re-train/tweak by bumping the exploration factor up and putting the weights.txt file copied in a new level.
• Placement algorithm added for finding empty spaces for helper shapes when level is loaded and during gameplay sometimes such as when teleporting your shape with the teleport ability