Added support for giving a function to engine.io to decide whether a request should be allowed or not when verifying. This is used by socket.io to check for allowed origins.
Added support for giving a function to engine.io to decide whether a request should be allowed or not when verifying. This is used by socket.io to check for allowed origins.

nkzawa/engine.io,CantemoInternal/engine.io,socketio/engine.io,socketio/engine.io,kapouer/engine.io