Changes to collider behavior

The collider now levitates above the ground, which makes small obstacles a non-issue. The raytest also helps the collider stick to staircases, so players don't jump off anymore.
Crouching now changes the collider to a smaller version, so now there is actual functionality to crouching.
I also removed the anchor from corpses of network players. I'm not entirely sure why this was done, but removing it doesn't seem to break anything.

Subsurface/Source/GUI/GUI.cs

@@ -200,6 +200,8 @@ namespace Barotrauma
                 GameMain.NetworkMember = null;
             }
 
+            CoroutineManager.StopCoroutines("EndCinematic");
+
             GameMain.GameSession = null;
 
             GameMain.MainMenuScreen.Select();