Optimisations

- Fixed issue with `InputFile` not setting file-name properly.
- Fixed issue with `InputFile` not setting the correct index when
posting certain arrays.
- Made Csrf-token cookie provider more versitile by creating new
`CookieTokenProvider` and `ITokenProvider` classes.
- Strict-checks optimisations.
- Updated documentation to reflect new changes.

helpers.php

@@ -73,7 +73,7 @@ function csrf_token()
 {
     $baseVerifier = Router::router()->getCsrfVerifier();
     if ($baseVerifier !== null) {
-        return $baseVerifier->getToken();
+        return $baseVerifier->getTokenProvider()->getToken();
     }
 
     return null;