Fixed in sample web site:
- Dir listing generated links

New features:
- Added new function to generate random 403 error pages for most common web servers: tomcat, IIS, nginx, apache.
- Added new function to generate random web server banners.
- Now, when /admin URL is requested, a random 403 page ir returned.
- Now, when sample site is loaded, a custom (and random) web server banner is generated. This banner is sent in each HTTP Response (in 'Server' field, in HTTP header) and reused for all responses.
- New wordlist added, with many banners of web servers.