Allow for option to disable "I have a password" checkbox in embeddable client

[CounterPillow]

For people using an embedded or linked-to prefilled client in the form of https://kiwiirc.com/nextclient/foo?channel=#bar, it could be useful to have an additional option &nopass or similar to hide the "I have a password" checkbox. The reason for this is that if such a chat is used for website support, people may be confused and think they have to input their password from the website, which obviously isn't going to work.

[prawnsalad]

This probably won't be in the URL, but we are nearing pushing live a client builder that will let you customise the client as you see fit. I'll update this issue once it's available