Makes Airtight ECS. (#4351)

* Makes Airtight ECS.

* Remove atmos holdovers while at it!

Content.Server/Atmos/Commands/RemoveGasCommand.cs

@@ -0,0 +1,46 @@
+using Content.Server.Administration;
+using Content.Server.Atmos.EntitySystems;
+using Content.Shared.Administration;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+
+namespace Content.Server.Atmos.Commands
+{
+    [AdminCommand(AdminFlags.Debug)]
+    public class RemoveGasCommand : IConsoleCommand
+    {
+        public string Command => "removegas";
+        public string Description => "Removes an amount of gases.";
+        public string Help => "removegas <X> <Y> <GridId> <amount> <ratio>\nIf <ratio> is true, amount will be treated as the ratio of gas to be removed.";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            if (args.Length < 5) return;
+            if(!int.TryParse(args[0], out var x)
+               || !int.TryParse(args[1], out var y)
+               || !int.TryParse(args[2], out var id)
+               || !float.TryParse(args[3], out var amount)
+               || !bool.TryParse(args[4], out var ratio)) return;
+
+            var gridId = new GridId(id);
+
+            var atmosphereSystem = EntitySystem.Get<AtmosphereSystem>();
+            var indices = new Vector2i(x, y);
+            var tile = atmosphereSystem.GetTileMixture(gridId, indices, true);
+
+            if (tile == null)
+            {
+                shell.WriteLine("Invalid coordinates or tile.");
+                return;
+            }
+
+            if (ratio)
+                tile.RemoveRatio(amount);
+            else
+                tile.Remove(amount);
+        }
+    }
+
+}