[pull] master from 4ian:master

.github/CODEOWNERS

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-* @4ian
+* @4ian
+Extensions/Firebase @arthuro555

Extensions/Firebase/A_utils/A_UIDArray.js

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+/**
+ * Firebase Tools Collection
+ * @fileoverview
+ * @author arthuro555
+ */
+
+/**
+ * A special array where push tries to reuse old unused indices.
+ * Why? This is for storing UIDs. You can see this as a sort of memory optimization:
+ * Each time an object is removed, it is replaced with null in the array.
+ * Then a new object can reuse that emplacement when pushing, instead of adding an element
+ * to the array. Technically the push function is not really pushing anymore,
+ * but the name is kept to make it easier for new devs to use (almost same API as classic array).
+ * @class
+ */
+gdjs.UIDArray = function () {
+  /**
+   * The internal array of UIDs.
+   * @type {Array<any>}
+   * @private
+   */
+  this._array = [];
+};
+
+/**
+ * Adds an object to the UIDs array and returns it's UID.
+ * @param {any} item - The item to assign a UID to.
+ * @returns {number} - The new UID of the object.
+ */
+gdjs.UIDArray.prototype.push = function (item) {
+  for (let i in this._array) {
+    if (this._array[i] === null) {
+      this._array[i] = item;
+      return parseInt(i);
+    }
+  }
+  return this._array.push(item) - 1;
+};
+
+/**
+ * Removes an element from the UIDs array by UID.
+ * @param {number} uid - The UID of the object to remove.
+ */
+gdjs.UIDArray.prototype.remove = function (uid) {
+  if (uid >= this._array.length) return; // Don't pollute the array with unecessary nulls.
+  this._array[uid] = null;
+};
+
+/**
+ * Get an element from the UIDs array by UID.
+ * @param {number} uid - The UID of the object to get.
+ */
+gdjs.UIDArray.prototype.get = function (uid) {
+  if (uid >= this._array.length) return null; // Prevent out of range getting.
+  return this._array[uid];
+};