Refactor third party

Refactored third party module configuration to make it simpler to add new modules. Only a module name and a description are required. This assumes that the only logic required is to check for the flag and add an --add-module flag for that module. For anything more involved, a depends_on line should be used.

This also includes a fix for an outdated shasum for the dav-ext, an incorrect share folder name for the subs-filter module, and adds a few modules.

Thanks @joprice
https://github.com/denji/homebrew-nginx/commit/c0a2301ddb998fe8c20735a23dd542543bf65ad8
https://github.com/denji/homebrew-nginx/commit/84fdc54245b41e05364215a07aca4424cfe02308

TODO
--
* [ ] [limit_upload_rate](https://github.com/cfsego/limit_upload_rate/) Limit upload rate for nginx
* [ ] [nginx-upload-module](https://github.com/vkholodkov/nginx-upload-module) Uploads using multipart/form-data encoding for nginx
* [ ] [ngx_http_php_memcache_standard_balancer](https://github.com/replay/ngx_http_php_memcache_standard_balancer) loadbalancer that is compatible to the standard loadbalancer in the php-memcache module
* [ ] [ngx_limit_tcp_module](https://github.com/chenbk85/ngx_limit_tcp_module) module used for limiting accept events and concurrent
* [ ] [ngx_hmux](https://github.com/sogou-op/ngx_hmux) Resin's hmux implementation in nginx
* [ ] [ngxsbs](https://github.com/kevin-a-naude/ngxsbs) NginX Server Block Sanitiser * [ ] ensures that user supplied NginX server config is well behaved in a larger/shared context.
* [ ] [ngx_mruby](https://github.com/matsumoto-r/ngx_mruby)
* [ ] [ngx_http_pinba_module](https://github.com/tony2001/ngx_http_pinba_module) Pinba module for nginx
* [ ] [ngx_aws_auth](https://github.com/anomalizer/ngx_aws_auth) nginx module to proxy to authenticated AWS services
* [ ] [ngx_image_thumb](https://github.com/3078825/ngx_image_thumb) Advanced Nginx Image Module
* [ ] [ngx_http_dyups_module](https://github.com/yzprofile/ngx_http_dyups_module) + merge patch Tengine
* [ ] [ngx_http_qrcode_module](https://github.com/dcshi/ngx_http_qrcode_module) Nginx to generate and serve QR code
* [ ] [ngx-lua-stats](https://github.com/skyeydemon/ngx-lua-stats) stats by ngx-lua
* [ ] [ngx_metrics](https://github.com/zenops/ngx_metrics) collect nginx responde code metrics and more
* [ ] [ngx_dosdetector](https://github.com/cubicdaiya/ngx_dosdetector) nginx module for detecting Dos attacks (alternative [anti-ddos](https://github.com/marcqualie/homebrew-nginx/blob/master/anti-ddos-nginx-module.rb))
* [ ] [ngx_req_status](https://github.com/zls0424/ngx_req_status) Request status in Nginx
* [ ] [ngx_http_extauth_download](https://github.com/arthurtumanyan/ngx_http_extauth_download) Secure download module for nginx
* [ ] [ngx_http_q_chash](https://github.com/hyuuhit/ngx_http_q_chash) nginx to use consistent hash for upstream, support args, auto retry
* [ ] [ngx_http_gif_magick](https://github.com/mschenck/ngx_http_gif_magick) nginx http filter module for dynamically resizing gifs with ImageMagick
* [ ] [ngx_secure_token](https://github.com/netdna/ngx_secure_token) Token-based authorization module for Nginx.
* [ ] [ngx_access_token](https://github.com/cubicdaiya/ngx_access_token) implement mod_access_token
* [ ] [ngx_http_response_module](https://github.com/catap/ngx_http_response_module)
* [ ] [ngx-sticky-module](https://code.google.com/p/nginx-sticky-module/) nginx module to add an upstream server persistance using cookies
* [ ] [ngx-http-tokenaccess](https://github.com/xiwan/ngx-http-tokenaccess) nginx module to control static resources's access through valid token
* [ ] [ngx_http_allow_methods_module](https://github.com/pschultz/ngx_http_allow_methods_module) Nginx module for allowing custom HTTP methods
* [ ] [ngx_http_ip_tos_filter_module](https://github.com/catap/ngx_http_ip_tos_filter_module) IP TOS module for nginx, implement smart QoS
and traffic shaping at firewall/router level
* [ ] [nginx_ssl_tack](https://github.com/kyprizel/nginx_ssl_tack) patch enables the NGINX SSL module to respond with a TACK TLS Extension

We need a patch
--
* [ ] [ngx_server_info_module](https://github.com/wujiangthu/ngx_server_info_module)
* [ ] [ngx_http_generate_secure_download_links](https://github.com/replay/ngx_http_generate_secure_download_links)