new registry formular, re #1559

app/controllers/registration.php

app/views/registration/index.php

app/views/registration/save.php

db/migrations/5.5.19_update_username_regular_expression.php

lib/classes/forms/ConfirmInput.php

lib/classes/forms/DatalistInput.php

lib/classes/forms/Form.php

lib/classes/forms/Input.php

lib/classes/forms/Part.php

lib/classes/forms/PasswordInput.php

lib/classes/forms/RadioInput.php

lib/classes/forms/RangeInput.php

lib/navigation/LoginNavigation.php

public/register1.php

public/register2.php

resources/assets/javascripts/bootstrap/forms.js

resources/assets/stylesheets/scss/forms.scss

templates/forms/confirm_password_input.php

templates/forms/datalist_input.php

templates/forms/form.php