Reorg of D site

[Walter Bright]

As some of you may have noticed, the D 2.0 stuff has all moved into 
digitalmars.com/d/2.0, instead of digitalmars.com/d. The original files 
have been replaced with redirects (phew, that was a lot of tedious work).

The benefit of this is that the searches are now targeted instead of 
picking up the whole digitalmars site. (It took about 24 hours for 
google to reindex the site.)