New Docs, better code

I've uploaded a brief update of the docs, just so that they're not miles behind the code.

I've also been working on a Boost.Spirit-based form_parser class for incrementally parsing POST data, session support (using Boost.Interprocess) and on allowing the library to be compiled separately.

As usual, see the Boost SVN Sandbox for current source (or the README in the sf.net SVN repo).

Cheers.