global config: set default channel settings for newly registered channels

[empus]

Overview

It is useful, especially for new Armour users, to setup sensible and useful default channel settings when a channel is first registered.

Done

• FLOATLIM: now enabled for new channels, unless cfg(float:auto) is disabled

To Do

• Consider adding a cumulative (rate-limited) blacklist regex entry for ^[^!]+~ and limit of 2:1:5 (or similar) to aid in floodnet detection.