Fixed the request line length check.
fix whitespaces
fix the correct remote address

The remote address should return the direct client addr not a forwarded
header.

This is a breaking change. The main problem with such changes is the way
the application or framework will handle the URL completion. Indeed most
of them are only expecting a TCP socket.

fix #633
Added extra valid request (099) and test (send_special_chunks).

``send_special_chunks`` sends the request data in two chunks, one having a length of 1 byte, which ensures there is no CRLF, and a second chunk containing the rest of the request data. Practically, this forces ``gunicorn.http.message.Request.read_line()`` to get the full request data with two buffer reads and reveal possible bugs related to the internal buffer mechanism. See #670 for more information.
dont' override SERVER_* by the Host header

Gunicorn shouln't override the SERVER_* by the Host header. The client
will take care about it during the URL reconstruction if needed.

Since the spec don't support unix sockets, Gunicorn is using the HOST
heeader when available to create viable SERVER_* if possible so the
application and framworks will be happy. When the Host Header is not
available (SocketPath, '') is returned.

fix #628
modify log_file option

Gunicorn should generally only bother writing its own log and let
the application handle the way it want to log its own errors.

Now the log_file option will be overriden by the gunicorn options
`--error-logfile` and `--access-logfile` if they are given.
don't propagate logs

fix #574
don't try to redirect stdout/stderr to the logfile.

Logging to a logfile should be explicit and gunicorn should not try to
be smarter here. Partially fix #591
make it explicit that we only send gunicorn logs to syslog.

follows suggestion in #548
allows possibility to set the driver used in syslog for unix sockets

This changes allows a use to set the driver used to send the data over a
unix socket. 'dgram' for a dgram driver or 'stream' for a stream driver.
'stream' is the default. The change is documented in the settings
documentation.

fix #671
fix logging.conf exampple
fix handle_eror, find the cfg object.
add a quick test to make sure we get the sys.stderr
make sure to redirect wsgi.errors when needed

By if the options ` --error-logfile` is set to '-' then wsgi.errors are
returned to sys.stderr, if any log file is passed either using the
log-config file or the option, Errors are written to the files.

By default no error is returned.
don't send wsgi.errors twice and remove spurious print
set wsgi.multithread to True for async workers

Also simplifies the environment handling in the gevent_pywsgi
server so that it also has this key. An added side effect is
that the gunicorn FileWrapper gets set for the gevent_pywsgi
worker, too.

Fixes #486
Merge pull request #670 from gnotaras/bugfix-request-line-check

Fixed the request line length check.