add support for password-protected channels

[ghost]

Freenode support channels which require password to join (option k in https://freenode.net/kb/answer/channelmodes). Would be nice to be able to use them with circe's autojoin facilities (once they're actually working - see #325 for details).

[jorgenschaefer]

People still use password protected channels? Wow :-) Yeah, would be nice to have support for that.

[ghost]

Curious, what alternatives for passwords are out there?

[jorgenschaefer]

I think the alternative is "do not use IRC channels on a public IRC server for non-public discussions", but that might not be an option for you. As people use it, would be nice if Circe's auto-join would support passwords.

[ghost]

I think it's more "keep the trolls away" rather than "hide from NSA" use-case :)

[jorgenschaefer]

You could look into the +i channel flag (invite-only) and use +I (invite exceptions) or chanserv for the invite control. But I don't want to talk you out of the channel password thing, really, just expressing astonishment as I have not seen password-protected channels in close to two decades :-D