Update releasenotes and version for release 0.24.0

Update for release 0.23.0

Update package metadata for preview01

Updates for v0.22 release

- Updated nuspecs
- Simplified MakePackage.ps1
- Added Sustainsys logo for Sustainsys.Saml2.AspNetCore2 package

Updated version number to 0.21.2 for release.

Updated version number to 0.21.1 for release.

Updated version number to 0.21.0 for release.

Updated version number to 0.20.0 for release.

Updated version number to 0.19.0 for release.

Updated version number to 0.18.1 for release.