3rd party modules list synchronized with FreeBSD nginx-devel port.

Non-quoted parameters are allowed to contain variables in curly brackets
(see d91a8c4ac6bb), so vim syntax rules were adjusted accordingly.

Instead of highlighting directives in arbitrary positions, proper
parsing of nginx.conf syntax was implemented, matching what nginx does
internally.  This allows vim to correctly highlight various complex cases,
including:

    return 301 http://example.com/path#fragment";

and also avoids highlighting of parameters as directives, as in

    server_name missing.semicolon.example.com
    index index.php;

where "index" is not a directive but a parameter of the "server_name"
directive due to missing semicolon.

Most important downside of this approach seems to be that there is no
easy way to introduce directive-specific parameters.  As such, only "listen"
directive parameters were preserved.

uwsgi is not a third-party module anymore. 'split_clients' is a new
block directive type. The directives were automatically extracted from
the ngx_command_t arrays, sorted in the C locale and inserted.

Trailing spaces got removed at some places.

I've been maintaining these scripts independently for a while now, even though
I'm no longer active in the community. Seems to me that contrib/ is a good
long-term home for the scripts.