It is now possible to specify a file with "config" as an application
configuration key in a paste deploy configuration file. This allows
paster applications to use the full range of gunicorn settings even
when using paste/pserve rather than gunicorn_paster.
Fixes#540.
Allows gunicorn to listen on different interface. It can be either ipv6,
unix or ipv4 sockets.
Ex:
gunicorn -w3 -b 127.0.0.1:8001 -b 127.0.0.1:8000 -b [::1]:8000 test:app
fix#444
