Merge pull request #9 from alanpearce/master

Add plist installer from nginx formula to allow launching from launchd
Added --with-http_sub_module argument for nginx

This commit enables the http_sub_module (http://wiki.nginx.org/HttpSubModule) for nginx using the --with-sub option.
Merge pull request #11 from durango/patch-1

Added --with-http_sub_module argument for nginx
Added support for --with-http_addition_module

Turns out this is what I really needed for reverse proxies (node, python, and ruby apps mostly).

This commit adds the HTTP addition module for nginx as documented here http://nginx.org/en/docs/http/ngx_http_addition_module.html 

The command to add HTTP addition module is ```--with-addition``` in order to maintain uniformity with the other modules/module options.

Hope this helps someone in the future as it did for me.
Merge pull request #12 from durango/patch-2

Added support for --with-http_addition_module
nginx-mainline 1.5.5
Update to 1.4.2.7