NSFW Chat channel added

Commands /nsfwchat and /nsfwtoggle can be used to: toggle or chat to
nsfw or: listen to nsfw chat respectively.

ACTUALLY COMMITING FILES THIS TIME
Formatting and functional fixes.
Adding NSFW filter in global chat, along with tests.
Adding /cpa command
Adding NSFW listening persistence
Moving package from supercheese -> uk.co.drnaylor.chatparty
This change reflects the relative amount of code in the
affected class.