timesheet export (#317)

* remove autocomplete for begin and end
* fix minute display in timesheet-edit form
* toolbar form label in separate row
* added export action

tests/Twig/ExtensionsTest.php

@@ -180,7 +180,7 @@ class ExtensionsTest extends TestCase
         $icons = [
             'user', 'customer', 'project', 'activity', 'admin', 'invoice', 'timesheet', 'dashboard', 'logout', 'trash',
             'delete', 'repeat', 'edit', 'manual', 'help', 'start', 'start-small', 'stop', 'stop-small', 'filter',
-            'create', 'list', 'print', 'visibility', 'calendar', 'money', 'duration',
+            'create', 'list', 'print', 'visibility', 'calendar', 'money', 'duration', 'download'
         ];
 
         // test pre-defined icons