1.1.0 Preview1 Release

Update buildtools version to 00517-05 (dotnet#9515)

Merge pull request dotnet#7964 from stephentoub/port7946

Port to RC2: Fix CurlResponseStream.Dispose to cancel the request

Merge pull request dotnet#4565 from ellismg/port-runtime-json-to-rc1

Add RIDs for OSX 10.11, OS.version, OSfamily-arch

Merge pull request dotnet#1643 from nguerrera/dispose-doc-fix

Fix incorrect documentation about parallel dispose

Merge pull request dotnet#1643 from nguerrera/dispose-doc-fix

Fix incorrect documentation about parallel dispose