Added WSF_EXECUTE_HANDLER as common ancestor for handler with `execute (WSF_REQUEST, WSF_RESPONSE) ..` routine.
Made more flexible a few routine by accepting ITERABLE instead of ARRAY, and READABLE_STRING_GENERAL when possible.
This fixes CQS violation from WSF_ROUTER.dispatch_and_return_handler (...): ? WSF_HANDLER
and related code, and this is more compliant with concurrency.
In addition, the WSF_ROUTER_SESSION can be enhanced in the future to answer more advanced needs.
kept `key' as redirection, and also string as obsolete redirection.
Router: provide a way to pass the request methods without using manifest string, thanks to WSF_ROUTER_METHODS
so instead of using manifest array or manifest strings, just create an instance of WSF_ROUTER_METHODS
for convenience, WSF_ROUTER provides a few `methods_...' returning prebuilt WSF_ROUTER_METHODS objects
Improved code related to unicode handling in URL, and parameters (before the framework was doing too much)
