通过nginx-extras安装nginx的组件
我们一般使用nginx的插件时，都会用nginx的源码，编译时加进去一些插件，但是有时我们直接用源安装，比如在deiban和ubuntu下面，apt-get install nginx，再来安装第三方的nginx插件就不太方便了。nginx-extras集成了一些常用的第三方的插件，直接安装就行了。
apt-get install nginx-extras
这时就已完成了大多数常用nginx插件的安装。
debian 7的nginx-extras介绍：https://packages.debian.org/zh-cn/wheezy/nginx-extras
This package provides a version of nginx with the standard modules, plus extra features and modules such as the Perl module, which allows the addition of Perl in configuration files.
STANDARD HTTP MODULES: Core, Access, Auth Basic, Auto Index, Browser, Charset, Empty GIF, FastCGI, Geo, Gzip, Headers, Index, Limit Requests, Limit Zone, Log, Map, Memcached, Proxy, Referer, Rewrite, SCGI, Split Clients, SSI, Upstream, User ID, UWSGI.
OPTIONAL HTTP MODULES: Addition, Debug, Embedded Perl, FLV, GeoIP, Gzip Precompression, Image Filter, IPv6, MP4, Random Index, Real IP, Secure Link, SSL, Stub Status, Substitution, WebDAV, XSLT.
MAIL MODULES: Mail Core, IMAP, POP3, SMTP, SSL.
THIRD PARTY MODULES: Auth PAM, Chunkin, DAV Ext, Echo, Embedded Lua, HttpHeadersMore, http push, Nginx Development Kit, Upload module, Upload Progress, Upstream Fair Queue.
nginx 1.4.2又增加了以下几项内容：
