Provides more detailed h2 configuration

[silence-coding]

H2 provides a large number of configurable parameters, but hyper exposes only some of them. It is recommended that hyper provide these parameters. Currently, some servers return REFUSED_STREAM because of max_concurrent_streams.

https://github.com/hyperium/hyper/blob/5243570137ae49628cb387fff5611eea0add33bf/src/proto/h2/client.rs#L72

[seanmonstar]

It's fine to add some more options to hyper's builders.

(I don't think any of them would help you with servers refusing streams...)

[silence-coding]

Thanks.

[kriogenia]

The missing configurable parameters right now seems to be: max_header_list_size, max_concurrent_streams, initial_max_send_streams, reset_stream_duration and max_send_buffer_size.

I can contribute to this if it's ok.