Coding standards and Documention.

1. Remove the fbl.admin.inc code.
2. Remove @file docblock in the FblConfiguration config form.
3. Remove the inline import
public function buildForm(array $form, \Drupal\Core\Form\FormStateInterface $form_state) {
public function validateForm(array &$form, \Drupal\Core\Form\FormStateInterface $form_state) {
4. Inject the entityManager in buildForm and validateForm instead using the service \Drupal::entityManager().
5. In _fbl_check_for_duplicates, _fbl_user_count and _fbl_field_data_count, Instead of db_select, inject the database service.
6. In all doc blocks, we should have the One line explaintion of the function.
7. Implement the hook_help, function fbl_help($path, $arg) {
8. Remove the inline import \Drupal\Core\Url::fromRoute, in hook_help.
9. Remove hook_menu(), hook_permission()
10. Remove unused functions.
function fbl_field_attach_validate($entity_type, $entity, &$errors) {
function _fbl_field_unique_check($field, $uid, $value) {