2.4.6 Windows Installer

[Keegan Witt]

The Windows installer for Groovy 2.4.6 is now available:
https://bintray.com/groovy/Distributions/Windows-Installer/groovy-2.4.6-
installer/view.  Now also includes Grengine
<https://github.com/jexler/grengine>.

-Keegan