Fix icsharpcode#1473: Handle default values for 'Prefer32Bit' correctly.

Use appropriate type for helper variables introduced for named argume…

…nts.

Prepare 4.0.1 hotfix release.

Set VersionName = null

Set VersionName = "rc2"

Set VersionName = "rc1"

Fix icsharpcode#1338: KeyNotFoundException in SwitchDetection.Analyze…

…ControlFlow()

Set VersionName = 'beta2'

Update nuspec properties for 2nd (beta1-based) test release of .NET C…

…ore tool

Update to latest -alpha1 on NuGet.org