Move Cookie to own class (with tests)

Move Authentication to App namespace

include/api.php

@@ -12,7 +12,7 @@ use Friendica\Content\ContactSelector;
 use Friendica\Content\Feature;
 use Friendica\Content\Text\BBCode;
 use Friendica\Content\Text\HTML;
-use Friendica\Core\Authentication;
+use Friendica\App\Authentication;
 use Friendica\Core\Config;
 use Friendica\Core\Hook;
 use Friendica\Core\L10n;