* Attempted to get asynchronous accepts working -- failed!  Entire portions of the library will have to be rewritten to accomplish this.
* Got synchronous accepts to be non-blocking when waiting for the next message (to facilitate shutting down when receiving SIGTERM.
* Now using boost asio local::stream::socket / ip::tcp::socket / windows::stream_handle direclty (and exclusively) to handle the fcgi connection (which could be tcp socket or a 'pipe').  This makes the win32_accept_service_impl.hpp pretty close to a cross-platform implementation.
* Fixed ugly bug in client.close() that was writing fcgi END packet when there was no request in progress!