- Readded BaseCsrfVerifier middleware.
- Csrf-token expire time is now updated on each page refresh.
- CSRF-token update now happens after the route has been loaded, to ensure
no faulty "Invalid csrf-token" exceptions.
- Added functionality to CsrfToken class.
- Added header support to Request class.
- Added option to set BaseCsrfVerifier class in RouterBase and
SimpleRouter.