Download page and D docs defaulting to D2

[Jarrett Billingsley]

I've had about eight people come into the D IRC channel in the past week 
asking why xxx was failing, or why something they thought should work 
(constness) didn't.  In every single case, it was either because they read 
the D2 docs, which are the default (FOR SOME REASON), and ended up 
downloading the D1 compiler, or because they downloaded the ancient 1.015 D1 
compiler which didn't have any bugfixes which have been implemented over the 
past seven months.

So; this is really starting to come to a head.  I don't know how many people 
have suggested switching the default D docs to the D1 docs.  D2 is _alpha_ 
and should be treated as such.  We _need_ to get this resolved.

Secondly, the D1 DMD D compiler download page 
(http://www.digitalmars.com/d/1.0/dcompiler.html) should be updated to point 
to the very newest version of the D compiler, or those hardlinks should be 
removed entirely and simply redirected to the changelog, which is far more 
up-to-date and lets people know what's been fixed.