handlers: permisison check for all pages + retrieve user-specific permissions for pages (if any)

handlers/handlerdefault.h

@@ -5,9 +5,10 @@
 class HandlerDefault : public Handler
 {
   public:
-	Response handle(const Request &r) override;
+	Response handleRequest(const Request &r) override;
 	~HandlerDefault() override;
 	using Handler::Handler;
+	bool canAccess(const Permissions &perms) override;
 };
 
 #endif // HANDLERDEFAULT_H