Websockets: error-handler could include reason

[MichaelSB]

I somehow miss information on the actual error in the error-handler of websockets. We have a string reason in the close-handler, but other than "some error happened" we get nothing in the error-handler. Maybe a string as well? For boost::system::error_code, we could use ec.message(). Other errors could just give some hardcoded string. Or probably some enum, which error-handlers could switch on? A combination (struct)? Opinions?

[MichaelSB]

Cool! Many thanks :)