enhanced plugin support (#634)

- refactored admin controller and templates
- plugin support for entity actions
- changed column mail to email in customer table
- refactored theme events

tests/Timesheet/UtilTest.php

@@ -0,0 +1,43 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Tests\Timesheet;
+
+use App\Timesheet\Util;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers \App\Timesheet\Util
+ */
+class UtilTest extends TestCase
+{
+    /**
+     * @dataProvider getRateCalculationData
+     */
+    public function testCalculateRate($hourlyRate, $duration, $expectedRate)
+    {
+        $this->assertEquals($expectedRate, Util::calculateRate($hourlyRate, $duration));
+    }
+
+    public function getRateCalculationData()
+    {
+        yield [0, 0, 0];
+        yield [1, 100, 0.03];
+        yield [1, 900, 0.25];
+        yield [1, 1800, 0.5];
+        yield [10000, 1, 2.78];
+        yield [736, 123.45, 25.15];
+        yield [736, 123, 25.15];
+        yield [7360, 1234.99, 2522.84];
+        yield [7360, 1234, 2522.84];
+        yield [7360.34, 1234, 2522.96];
+        yield [7360.01, 1234, 2522.85];
+        yield [7360.99, 1234, 2523.18];
+    }
+}