Progress tracking

[Chaoses-Ib]

nyquest already supports streaming, but progress tracking is still listed in future works in README. Does it just mean there isn't a convenient API and the user needs to track it with Read/Write, or is there any pitfalls?

[bdbai]

@Chaoses-Ib While you can already use the existing streaming API today to track transfer progress manually, the metrics may not be accurate due to various factors in the backend implementations, such as internal buffering and automatic decompression etc.

The goal of the progress tracking feature is to expose native progress APIs from the backends. Specifically, these are

• HttpProgress from WinRT HttpClient
• NSURLSessionTask progress
• CURLOPT_XFERINFOFUNCTION from libcurl