haskell wikibook moves forward

Ran into dmhouse on #haskell today. One bit of conversation led into another, and before I knew it I was rewriting the entirety of the basic concepts (now called Variables and functions) chapter. I hope it doesn't suck too badly, but I guess I'm not too worried, since the community can always come in and clean up after me later. Also completed the Write Yourself a Scheme in 48 Hours import. It was easy, thanks to the Perl module HTML::WikiConverter.