#167 added test for UserBanChecker
#167 added a user ban system
#182 Fixes and refactoring
#182 Refactoring and bugfixes in the guestbook module
Fixed checking roles and rights.
#206 Removed AuthMiddleware. Some refactoring
#206 Added HasPermissionMiddleware and HasRoleMiddleware. Refactoring.
#182 Added guestbook permissions
Improved installation process