Update httpclient to 4.3.1

[code4craft]

httpclient 4.3.1 has changing API with more features. Update httpclient to 4.3.1 and use more features in it.

[code4craft]

Done

[code4craft]

Use Kr36NewsModel for test, in 0.3.2 it takes 20 seconds to download 256 pages when in 0.3.3 it just takes 11 seconds. Nearly 90% performance enchancement.