[skion]

Agree with this, even if just done in one reference language. It is much easier for the community to port an existing binding to other languages, than to implement a new client from scratch.

Two notes:

2) No need to mask requests with a HEAD; a GET can also return a 304 directly.

6) De-duplication of calls: Any method except POST should be idempotent already, hence also a retry-on-error is trivial in those cases.