[Add] add ExpectContinue property in WebHDFSClient's constructor.

[spyteric]

Add an optional parameter ExpectContinue in constructor, let user decide the server return Continue(100) before success or not.

[risdenk]

What about defaulting the ExpectContinue parameter to false automatically? You should be able to try this by making your own HTTPClient.

Something like forcing this:

_httpClient.DefaultRequestHeaders.ExpectContinue = False

[spyteric]

So change the parameter of WebHDFSClient 's constructor to

bool ExpectContinue = false

instead of

bool? ExpectContinue = null

And _httpClient is create inside the constructor,
Could I make my own _httpClient?

[risdenk]

I think we can just hardcode the ExpectContinue = false and not have it as a constructor parameter at all. I thought that httpClient was exposed as a constructor argument but I was mistaken. I'm hoping that a one line change in total would fix this issue. I don't think we need to make ExpectContinue user configurable.

[spyteric]

So, add bool ExpectContinue = true into constuctor as default.
and PR again?
In my case, server will do return "continue 100" before success.

[risdenk]

Does the server still return continue 100 even if the ExpectContinue = False?