Release of v4.1.1-alpha1

Move all banners to GitHub. Adds library phpspreadsheet to JCB. Add import item example to demo component. Updates the Superpower class with the GetRemote class in the plugin. Ensures the super power autoloader triggers the correct repositories.

libraries/phpspreadsheet/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Queue.php

@@ -0,0 +1,56 @@
+<?php
+
+/**
+ * A simple array-backed queue, based off of the classic Okasaki
+ * persistent amortized queue.  The basic idea is to maintain two
+ * stacks: an input stack and an output stack.  When the output
+ * stack runs out, reverse the input stack and use it as the output
+ * stack.
+ *
+ * We don't use the SPL implementation because it's only supported
+ * on PHP 5.3 and later.
+ *
+ * Exercise: Prove that push/pop on this queue take amortized O(1) time.
+ *
+ * Exercise: Extend this queue to be a deque, while preserving amortized
+ * O(1) time.  Some care must be taken on rebalancing to avoid quadratic
+ * behaviour caused by repeatedly shuffling data from the input stack
+ * to the output stack and back.
+ */
+class HTMLPurifier_Queue {
+    private $input;
+    private $output;
+
+    public function __construct($input = array()) {
+        $this->input = $input;
+        $this->output = array();
+    }
+
+    /**
+     * Shifts an element off the front of the queue.
+     */
+    public function shift() {
+        if (empty($this->output)) {
+            $this->output = array_reverse($this->input);
+            $this->input = array();
+        }
+        if (empty($this->output)) {
+            return NULL;
+        }
+        return array_pop($this->output);
+    }
+
+    /**
+     * Pushes an element onto the front of the queue.
+     */
+    public function push($x) {
+        array_push($this->input, $x);
+    }
+
+    /**
+     * Checks if it's empty.
+     */
+    public function isEmpty() {
+        return empty($this->input) && empty($this->output);
+    }
+}