These are different from the loadable factoid modules. The factoid modules
are external executable shell commands that take stdin as arguments and print
to stdout as a return value. As such, they are not integrated into the bot
and cannot make use of the bot's internal subroutines.
These plugins are loaded internally and integrated into the bot such that they
can interface with the bot's internal subroutines and state.
All files in the Pluggable directory not beginning with an underscore will be
automatically loaded at bot start-up.
Plugins (including those starting with an underscore) can be manually loaded
or unloaded with the `plug` and `unplug` commands. Use `pluglist` to list
loaded plugins.
