Bunch of changes including mpdf library for creating pdf of invoices. It now attaches a PDF invoice when marked sent. Don't mark invoice_status sent if it partial or paid, removed green text from balance under clients only use red if the client has a balance and some other cleanups were done

vendor/myclabs/deep-copy/src/DeepCopy/deep_copy.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace DeepCopy;
+
+use function function_exists;
+
+if (false === function_exists('DeepCopy\deep_copy')) {
+    /**
+     * Deep copies the given value.
+     *
+     * @param mixed $value
+     * @param bool  $useCloneMethod
+     *
+     * @return mixed
+     */
+    function deep_copy($value, $useCloneMethod = false)
+    {
+        return (new DeepCopy($useCloneMethod))->copy($value);
+    }
+}