DEVELOPER-1080 Added Data Virtualization version 6.1.0.ALPHA Jar file to dowloads

I switched the current version to the ALPHA release, so it is now the displayed download.  I can switch items around if we would like to have the general release available first and the alpha release after.  

Also, I didn't see any documentation or other files available to add to the download manager yet, but I can add them as well when they become available.
Don't change this for pre-GA releases. Otherwise, the main download is set, in this case, to the ALPHA. Leaving the GA here, causes the ALPHA to appear as an additional download.