Added FOSUserBundle to composer dependencies.

Use
$ php composer.phar update friendsofsymfony/user-bundle
to install it.
Load FOSUserBundle on application bootstrapping.
Added User Entity.

Use
$ php app/console doctrine:schema:update --force
to update your database scheme.
Configured FOSUserBundle firewall to secure /admin.
Moved admin pages to /admin/ paths.

To use them, create a user using
$ php app/console fos:user:create testuser test@example.com password
and grant admin privileges
$ php app/console fos:user:promote testuser ROLE_SUPER_ADMIN
Added admin homepage
Merge branch 'master' of github.com:Binaerpiloten/freizeitbooking-plattform

Conflicts:
	composer.lock