patch applied (/haskell/ghc): Add 6.8.1 download page

[Claus Reinke]

> Sat Nov  3 09:46:04 EDT 2007  Ian Lynagh <igloo at earth.li>
>  * Add 6.8.1 download page
> 
>    A ./download_ghc_681.html

i had a quick look through the release notes, and found
two issues that might be removed before release:

1 the () defaulting in ghci looks highly dubious to me;
    having an 'instance Num ()', as given in the doc example,
    means that all arithmetic will fail, suggesting that this hack 
    is far too intrusive:

        *Main> 1+2
        *** Exception: def.hs:1:0: No instance nor default 
                method for class operation GHC.Num.+

    instead of meddling with a wide-ranging and subtle
    feature like defaults, wouldn't it be easier to switch 
    off ghci's printing of io-results? or use the old standby

        void m = m >> return ()

    in any case, it would be nice to have a ':show defaults'
    or something, so that one can see what is going on, and
    wrong.

2 while looking up 8.3.7, i saw this note in 8.3.6, on
    postfix operators:

    "(No Haskell 98 programs change their behaviour, of course.)" 

    like so many "of course" notes, this is wrong, of course;-)
    haskell98 has seq, and that makes eta-expansion observable.

    $ /cygdrive/c/ghc/ghc-6.4.1/bin/ghc -e 
        'let (!) a = undefined in (undefined !) `seq` True'
    True

    $ /cygdrive/c/ghc/ghc-6.6.1/bin/ghc -e 
        'let (!) a = undefined in (undefined !) `seq` True'
    *** Exception: Prelude.undefined

ah well, too late, the announcement is out already, i see. 
still, the docs for 8.3.6 should be fixed, and the () 
defaulting for ghci should be revisited, i think.

claus