added composer files and installed vendor packages. Also modified xsls to display base project

vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/ExceptionHandler.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheet\Calculation;
+
+class ExceptionHandler
+{
+    /**
+     * Register errorhandler.
+     */
+    public function __construct()
+    {
+        /** @var callable $callable */
+        $callable = [Exception::class, 'errorHandlerCallback'];
+        set_error_handler($callable, E_ALL);
+    }
+
+    /**
+     * Unregister errorhandler.
+     */
+    public function __destruct()
+    {
+        restore_error_handler();
+    }
+}