Changing Friendica\App\Mode from static methods to public methods

- Changing from static methods to public methods
- Adding dev-composer-dependency Mockery for static method mocking (f.e. Config, DBA)
- Adding ModeTest with Mocking
- removing bootstrap from phpunit.xml because of double loading tests\bootstrap.php

bin/auth_ejabberd.php

@@ -54,7 +54,7 @@ require_once "include/dba.php";
 
 $a = new App(dirname(__DIR__));
 
-if (App\Mode::isNormal()) {
+if ($a->getMode()->isNormal()) {
 	$oAuth = new ExAuth();
 	$oAuth->readStdin();
-}
+}