Re-publish & update old parsec manual

Extracted from #22.

@gbaz:

> It would actually be very good if we could also pull the documentation from the homepage (as hosted by web.archive.org: http://web.archive.org/web/20140329210442/http://legacy.cs.uu.nl/daan/download/parsec/parsec.html) and ported the parts that aren't just haddocks into a new parsec documentation module or the like, and put some very simple "getting started" bits from them at the top of the main Text.Parsec module. (having updated them to work with the latest parsec).
>
> Additionally there should be some top level documentation in the package indicating that that is the main entry point, and also which modules only remain for compatibility...

@aslatter:

> I haven't heard from Daan Leijen that it would be okay to copy his text verbatim elsewhere, so anything pulled in to the package description or module documentation would need to be new text.

@gbaz:

> did he just not reply to your email? did you try with a relatively recent address such as that in this paper (http://research.microsoft.com/pubs/210640/paper.pdf) ?
>
> I hope we can get in touch with him, because it would be much easier to do things that way, and I can't imagine he would object, even if it is slow to get a response and get his approval...

@aslatter:

> Yeah, that's the email I tried. It was a ways back.