Remove unused usings.

[tkirill]

Hi all!

This PR contains not so useful changes but at least this makes my ReSharper happy. 😃

Affects:

• src\Nest
• src\Profiling
• src\Serialization
• src\Tests

It doesn't affect src\CodeCompletion and src\Elasticsearch.Net because I'm not sure what code is generated and what isn't.

[Mpdreamz]

Woah thanks @tkirill

Will gladly pull this in but will have to ask you to sign our CLA before I may do so:

http://www.elasticsearch.org/contributor-agreement/

Thanks in advance.

[tkirill]

@Mpdreamz Oh, I completely forgot about this! I'm going to do this right now.

[Mpdreamz]

@tkirill @gmarz and discussed this and as is we decided we can't pull it in just yet since it also removes

using System;
using System.Collections.Generic;
using System.Linq;

Which we have set to never remove these in resharper.

[tkirill]

@Mpdreamz OK, I set to never remove these namespaces too and then removed unused usings again. It still doesn't affect src\CodeGeneration and src\Elasticsearch.Net.

I would be grateful if you could explain reasons why do you have these exclusions? I see it for the first time and it is pretty interesting.

[gmarz]

@tkirill The main reasoning behind leaving those namespaces, especially System, is because they contain many of the basic .NET classes that you would just expect to be there without having to manually add a using for. In the case of NEST, we make heavy use of Linq and generics, so a lot of the time we rely on System.Linq and System.Generic.Colletions already being there. It's just simply for convenience ;).

Thanks for updating your PR, we'll take another look and re-consider pulling it in.

[Mpdreamz]

Thanks for the PR @tkirill I'm sure this will settle some folks OCD 👍