Release bits for AppVeyor

AppVeyorReleaseBits.ps1

if ($env:APPVEYOR_REPO_TAG -eq $true -and $env:APPVEYOR_REPO_TAG_NAME  -match "^v\d+\.\d+\.\d+(-(?<prerelease>[\w\d]+))?$")
{
        $env:TaggedForRelease = $true
        $env:TaggedForPreRelease = $matches.prerelease -ne $null
        $relName = if ($env:TaggedForPreRelease) { "PreRelease" } else { "Release" }
        Add-AppveyorMessage "Tagged For $($relName): $($env:APPVEYOR_REPO_TAG_NAME)" -details $env:APPVEYOR_REPO_COMMIT
        Update-AppveyorBuild -Version "$env:APPVEYOR_REPO_TAG_NAME".Substring(1)
}