minimal install instructions:

- configure nginx with

./configure --add-module=/path/to/mapcache/nginx

the supplied nginx.conf contains an example configuration to load mapcache.
the relevant part is:

        location ~ ^/mapcache(?<path_info>/.*|$) {
           set $url_prefix "/mapcache";
           mapcache /home/tbonfort/dev/mapserver-trunk/mapcache/mapcache.xml;
        }

the <path_info> and $url_prefix are important and are used by mapcache
to parse the incoming requests.

before running nginx, set LD_LIBRARY_PATH to where libmapcache was installed if that 
is a non standard location.