Water flow logic tweaking:

- Less fluctuation, water doesn't constantly flow back and forth through gaps.
- Flowing water pushes characters around much more heavily, and the force is applied to the collider in addition to the limbs.
- Vertical gaps don't push characters up/down unless the character is roughly above/below the gap.

+ Renamed some fields in the hull and gap classes (Volume -> WaterVolume, FullVolume -> Volume, public fields start with a capital letter)

Barotrauma/BarotraumaClient/Source/GameSession/GameModes/Tutorials/BasicTutorial.cs

@@ -370,7 +370,7 @@ namespace Barotrauma.Tutorials
                 (commandDoor1.IsOpen || (commandDoor2.IsOpen || commandDoor3.IsOpen)))
             {
                 //prevent the hull from filling up completely and crushing the player
-                steering.Item.CurrentHull.Volume = Math.Min(steering.Item.CurrentHull.Volume, steering.Item.CurrentHull.FullVolume * 0.9f);
+                steering.Item.CurrentHull.WaterVolume = Math.Min(steering.Item.CurrentHull.WaterVolume, steering.Item.CurrentHull.Volume * 0.9f);
                 yield return CoroutineStatus.Running;
             }
 
@@ -589,7 +589,7 @@ namespace Barotrauma.Tutorials
 
             infoBox = CreateInfoFrame("The pump is up and running. Wait for the water to be drained out.");
 
-            while (pump.Item.CurrentHull.Volume > 1000.0f)
+            while (pump.Item.CurrentHull.WaterVolume > 1000.0f)
             {
                 yield return CoroutineStatus.Running;
             }