Add http 504 codes

[kingster]

Adding these extra status codes. Without these entries, if returned crow returns default 500, error code.

[The-EDev]

Well, 208 was meant to be used with WebDAV, a technology Crow doesn't support. And AFAIK Crow doesn't have the proper mechanisms to return a 408 (Which shouldn't be something a Crow app manually reports). Can you elaborate on how you're using these 2 status codes?

[The-EDev]

I should add that not returning a 408 isn't strictly in violation of the protocol.

[kingster]

Hmm, for 208, yes I agree, it's outside what crow supports today, so I could maybe use a better response code.

For 408, in my app, crow calls another service, and if that downstream service timeout, then it returns 408 as a response to the caller.

[The-EDev]

For the second case I think returning a 500 might be more appropriate since The downstream service itself is returning 408 whereas the connection between the Crow app and the client could be fine.

[kingster]

Agreed. Probably 504 makes more sense here. What do you think?

[The-EDev]

It does, and there's precedent in it being there since 502 Bad Gateway is there already.

[kingster]

Updated the PR with 504 code instead.

[The-EDev]

Merged. Thank you for your help!