Add possibility to upgrade the current session to a new TCP handler

[mfelsche]

and add a Websocket example demonstrating this new feature.

[SeanTAllen]

@mfelsche seems like we should add github.com/mfelsche/pony-websocket as a ponylang project. Are you up for doing that?

[SeanTAllen]

Or perhaps @mfelsche, would it make sense to incorporate github.com/mfelsche/pony-websocket into this library?

[SeanTAllen]

This needs release notes.

[SeanTAllen]

If the websocket library isn't a ponylang project then the example shouldnt be part of this repo. The build could be broken by the websocket library falling out of date and maintainers for this package who aren't Matthias wouldn't be able to fix without removing the example.

I think either example goes or we commit to making the websocket library a ponylang project.

IF we go for "example goes", then I think we should take the example and it can be an example repo unto itself OR we can do a blog post on the website after this is released with an example (and perhaps some FAQ fun on the website).

[SeanTAllen]

@mfelsche for the largest question first so we can move this along, do you want to pull the example out that relies on an external 3rd party library out and use some other location to detail the example or do you want to have the websockets library become a ponylang project that we make sure works with pony language changes going forward?

[sacovo]

Maybe remove the example for now, and if/when the websocket library is a ponylang project it can be added back in?

[mfelsche]

Sorry for the late reply. In order to move this forward, lets for now move this example out. I will improve the documentation of the upgrade_protocol behaviour. @sacovo Does this as is solve your use case for websocket support?

[sacovo]

Yes, it does. Thank you for your work!