Merge branch 'master' of github.com:Terradue/DotNetOpenSearch
partial
Better Http handling error
elasticcas

Signed-off-by: Emmanuel Mathot <emmanuel.mahot@gmail.com>
Merge branch 'refs/heads/elasticcas' into atom-opensearchable

Signed-off-by: Emmanuel Mathot <emmanuel.mahot@gmail.com>

Conflicts:
	Terradue.OpenSearch/Terradue/OpenSearch/Engine/Extensions/RdfOpenSearchEngineExtension.cs
	Terradue.OpenSearch/Terradue/OpenSearch/Result/AtomFeed.cs
	Terradue.OpenSearch/Terradue/OpenSearch/Result/IOpenSearchResultCollection.cs
	Terradue.OpenSearch/Terradue/OpenSearch/Result/RdfXmlDocument.cs