updated csproj file
implemented clear_scroll API

Conflicts:
	src/Nest/IElasticClient.cs
	src/Tests/Nest.Tests.Integration/Core/Suggest/SuggestTests.cs
Merge branch 'master' of github.com:elasticsearch/elasticsearch-net

Conflicts:
	src/Nest/IElasticClient.cs
	src/Nest/Nest.csproj
	src/Tests/Nest.Tests.Integration/Core/Suggest/SuggestTests.cs
	src/Tests/Nest.Tests.Integration/Nest.Tests.Integration.csproj
added ClearScroll(scrollId) extension method