Re-organized the Emacs page on HaskellWiki

[Christopher Done]

Hi chaps,

Yesterday I re-organized the Emacs so that the main page is now:

http://www.haskell.org/haskellwiki/Emacs

(The old link redirects here.)

The various topics of interested have been separated into pages and
linked to from the “infobox” on the right-hand side. Before, we threw
everything onto one big page, t'was a mess. Preferably we should keep
it organized and up to date. Anything related to Emacs and Haskell can
be put in here, not just haskell-mode stuff.

Ideally, we could make it very well documented with screenshots and
such, so that a complete newb to Emacs could get going quickly. But
that takes some time. If anyone does start that, let's standardize on
the default Emacs GTK+ black-on-white theme.

Ciao!