Add cutoff for nikky/nikkybot nick swap experiment
Slight reorganization
Ability to not highlight people on request

They can tell it "don't highlight me" and it will
stick a character in whenever it says their nick
to avoid highlighting them
Fix bot chat after preferred keywords data was moved to DB

Add special persistent data IDs to enable
bot-chat-specific configuration/state.
Make dedicated debug function; fix many cases where debug output appeared even with it disabled
Make ‘?’ prefixes for public commands optional
Add some public info; add ‘help’ command linking to it