ACTION-808: Arrange the funeral of Techniques

As agreed during the 3 July 2008 call, I replaced the shared techniques 
wiki page altogether by a static simple page that explains that the 
techniques are neither maintained nor accessible anymore.

See: http://www.w3.org/2005/MWI/BPWG/techs/TechniquesIntro

Any comments on the wording welcome.

Francois.