CMS 11 compatible release

This release adds support for CMS 11.

Thanks to @ErikxNilsson for the PR that support the changes in the v11 API.

Both the blop provider and the blob converter is now available in the Episerver Nuget feed.

PM> Install-Package EPiCode.SqlBlobProvider

PM> Install-Package EPiCode.BlobConverter

Bugfix release

This release works around a tricky bug that can crash the application pool in some cases by using a non seekable memory stream.