add favicon.ico

- copied from dlang.org
improve https and http configurability

- ssl-cert: set combined certificate/private key file

- https-port: set HTTPS port

- http-port: set HTTP port
  forwards to HTTPS iff it's configured
use yuglify to generate minified css and js
always use SIGINT
fix Issue #27 - killing sandbox doesn't work

- SIGINT was eaten by the python sandbox tool

- fixed by directly using seunshare which will
  forward SIGINT