st: Update to -shuffle- on SSC

["Jann, Ben" <ben.jann@soz.gess.ethz.ch>]

Thanks to Kit Baum, the -shuffle- package has been
updated on SSC.

Thanks to Mata (!), -shuffle- is much faster now.

To install, type

 . ssc install shuffle, replace

The old Stata 8 version of the package is now 
available as -shuffle8-.

ben

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/