Numbering Nginx conf files

[stuartpb]

Since Nginx sorts included files alphabetically and order of stuff can matter (like how the first defined server gets default_server status), I think scripts like apps.conf and the conf files inside each app directory should be number-prefixed.

[stuartpb]

This issue affects all Nginx plugins. I guess I'll file it against plushu/plushu-nginx, even though nothing actually uses plushu/plushu-nginx.