Add task and project API formatters

app/Formatter/TasksApiFormatter.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Kanboard\Formatter;
+
+use Kanboard\Core\Filter\FormatterInterface;
+
+/**
+ * Class TasksApiFormatter
+ *
+ * @package Kanboard\Formatter
+ */
+class TasksApiFormatter extends BaseFormatter implements FormatterInterface
+{
+    protected $tasks = array();
+
+    public function withTasks($tasks)
+    {
+        $this->tasks = $tasks;
+        return $this;
+    }
+
+    /**
+     * Apply formatter
+     *
+     * @access public
+     * @return mixed
+     */
+    public function format()
+    {
+        if (! empty($this->tasks)) {
+            foreach ($this->tasks as &$task) {
+                $task = $this->taskApiFormatter->withTask($task)->format();
+            }
+        }
+
+        return $this->tasks;
+    }
+}