implements #1083 Get Index Api
Merge branch 'develop' into feature/get-index

Conflicts:
	src/CodeGeneration/CodeGeneration.LowLevelClient/ApiEndpoints/root.html
	src/Nest/IElasticClient.cs
	src/Nest/Nest.csproj
	src/Tests/Nest.Tests.Unit/BigBadUrlUnitTests.cs
added missing constructors
Merge pull request #1119 from elasticsearch/feature/get-index

implements #1083 Get Index Api