Fixes xmldoc warnings from .net build.
Fixes issue where xmldocs were not being built in the release configuration but only in debug configuration.
Adds sandcastle specific xmldoc markup to enable inheriting comments from the interface were the implemented member is defined.
more docwarning fixes.
Simplified <see cref...> tags.
Added seealso xrefs or other appropriate cross referencing documentation.
More review and cleanup of missing documentation and broken links.