aligned with OpenSearch 1.7.7

Signed-off-by: Emmanuel Mathot <emmanuel.mathot@gmail.com>
added addins

Signed-off-by: Emmanuel Mathot <emmanuel.mathot@gmail.com>
[Terradue.OpenSearch.Kml] Implemented serialization methods
[Terradue.OpenSearch.Kml] Implemented IOpenSearchResultCollection members
Release version 1.0.0
Merge branch 'releases/release-1.0.0'