- More small caves in levels.

- Groups of crawlers, mantises and husks can spawn inside the caves.
- Salvage mission variants where the artifact spawns inside a cave.
- Fixed ruins being placed inside the sea floor.
- MonsterEvents don't spawn the monsters if no suitable spawn position is found.

Barotrauma/BarotraumaClient/Source/Map/Levels/LevelRenderer.cs

@@ -1,6 +1,7 @@
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using System;
+using System.Collections.Generic;
 using Voronoi2;
 
 namespace Barotrauma
@@ -190,6 +191,18 @@ namespace Barotrauma
                         GUI.DrawRectangle(spriteBatch, new Vector2(point.X, -point.Y), new Vector2(10.0f, 10.0f), Color.White, true);
                     }
                 }
+
+                foreach (List<Vector2> nodeList in level.SmallTunnels)
+                {
+                    for (int i = 1; i<nodeList.Count; i++)
+                    {
+                        GUI.DrawLine(spriteBatch, 
+                            new Vector2(nodeList[i-1].X, -nodeList[i - 1].Y),
+                            new Vector2(nodeList[i].X, -nodeList[i].Y), 
+                            Color.Lerp(Color.Yellow, Color.Red, i / (float)nodeList.Count), 0, 10);
+
+                    }
+                }
             }
 
             Vector2 pos = new Vector2(0.0f, -level.Size.Y);