Options to control closing behavior

[oberstet]

It would be helpful to have 4 options for the behavior after opening handshake has been completed:

1. leave open
2. perform WebSocket closing handshake (as now)
3. perform orderely close of TCP connection
4. just hard drop the TCP

1 This is useful to test scalability of server wrt maximum open WebSocket connections.

3 This is useful to test scalability for this scenario: a plain old Web site (with multiple HTML pages, not single-page Web app), that has some embedded JS which opens a WS. Think somelike like Google Analytics. When a user click a link or closes the tab, the browser will not perform a WebSocket closing handshake. In fact, it will never do, unless explicitly asked for.

4 This is useful to test how the server behaves when TCP are just hard dropped. DoS resistence, or when there are networking issues.

That could be a command line option like --close keepopen, --close wsclose, --close tcpclose or --close tcpdrop.