Support PASS command

http://tools.ietf.org/html/rfc1459#section-4.1.1 Add an input field in the server data forms, and send a PASS command with the given password if set by the user, before the NICK+USER commands.

(from redmine: created on 2015-06-03, closed on 2015-09-18)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information