add new Signed nupsecs
Add new ModelFilter and ModelPropertyFilter extensibility hooks for Swagger API
Expose ModelFilter and ModelPropertyFilter on SwaggerFeature
Move the swagger model filters at the end after default behavior has been applied.
Update swagger to use the latest swagger-ui - add catchall handler for /swagger-ui/ that replaces static url with /resources
remove debug code in SwaggerFeature
Add more StringUtils tests
Change all refs to sn SS.Interfaces to use pre-built version in /lib. Remove SS.Interfaces from sln build as requires sn-key.

Add SS.Interfaces Description attr, change all refs to use new
x.GetDescription() ext methods.
Upgrade SS.Text dll
Merge GetDescription ext methods
Update tests to check description in specific-attr first