small bugfixes (#2655)

* improve report visibility
* fix timesheet duration, which breaks validation
* added contributing section in README
* do not allow to change project for existing activities - fixes #2576
* bump theme version to fix FOSUserBundle dependency
* use entity color instead of inherited one - fixes #2200

src/Reporting/ProjectDetails/ProjectDetailsForm.php

@@ -32,6 +32,7 @@ class ProjectDetailsForm extends AbstractType
     public function buildForm(FormBuilderInterface $builder, array $options)
     {
         $builder->add('project', ProjectType::class, [
+            'ignore_date' => true,
             'required' => false,
             'label' => false,
             'width' => false,