feat: layered and roomed

packages/entity/traits/layered.js

@@ -0,0 +1,24 @@
+import {Trait} from '@avocado/entity';
+
+export class Layered extends Trait {
+
+  initialize() {
+    this._layer = undefined;
+  }
+
+  destroy() {
+    delete this._layer;
+    this.entity.emit('removedFromLayer');
+  }
+
+  get layer() {
+    return this._layer;
+  }
+
+  set layer(layer) {
+    this._layer = layer;
+    this.entity.emit('addedToLayer');
+  }
+
+}
+

packages/entity/traits/roomed.js

@@ -0,0 +1,23 @@
+import {Trait} from '@avocado/entity';
+
+export class Roomed extends Trait {
+
+  initialize() {
+    this._room = undefined;
+  }
+
+  destroy() {
+    delete this._room;
+    this.entity.emit('removedFromRoom');
+  }
+
+  get room() {
+    return this._room;
+  }
+
+  set room(room) {
+    this._room = room;
+    this.entity.emit('addedToRoom');
+  }
+
+}