Make Flashsocket port configurable

[cyraxx]

Currently, the port Flashsocket listens on is hard-coded to 843.

In my setup, I have to run it on a different port and then let the firewall forward port 843 there. It would be nice if this was possible without having to patch socket.io.

(Note: I understand that it must be reachable on port 843 from the outside because it's hard-coded in the Flash client. My firewall redirect takes care of that.)

[rauchg]

Currently we serve the flash policy over the same port, no 843 required anymore.

[cyraxx]

You're right. Didn't notice that, sorry.