Set version to '16.4'

Set version to '16.3'

Merge pull request microsoft#146 from AArnott/reduceTFMs

Remove older Target Frameworks

Set version to '16.1'

Merge remote-tracking branch 'upstream/v15.8'

Merge pull request microsoft#109 from AArnott/fix108

Avoid torn state race condition in RuntimeImport.IsLazy

Fix missing licenseUrl

Ship 15.8 as a stable package

Merge branch 'v15.6'

Remove -beta suffix from version