Default author is set in KoreBuild script

- If there is a non-empty env var "K_AUTHOR", use its value as default
  author
- Otherwise, use the value of predefined var "AUTHORS"
Change the author of package to MS OpenTech
Bump versions to *-alpha2-*
Updated kvm.ps1
Adding universe build target for init-release

Creates release branch and updates NuGet.config as appropriate
Modify KoreBuild to not set a K_BUILD_VERSION if it is already set (CI scenarios)