x86-64 Tango

[Kris]

Tango has historically had a hard time on x86-64 because of issues regarding 
_argptr and the Layout module (string formatting). David Friedman has been 
aware of the issue, and is considering resolutions.

In the meantime, I thought it worthwhile letting people know that David 
Brown has injected a patch to work around the problem (a big thank-you to 
David), and string-formatting is now operational on that platform. The SVN 
version of Tango is patched accordingly ...