Extra overload for convenience :)
Added test for #204 to proof ICollections should serialize fine
Merge branch 'master' of https://github.com/Mpdreamz/NEST

Conflicts:
	src/Nest/ElasticClient-Index.cs
post merge lost BulkIndexPath method from bb21371047a7
Merge pull request #207 from q42jaap/bulk-api-parentmissing

Extra for Parent() overload for convenience :)
test to help display proper type usage for issue #211