trivial plugin comment update
feature (plugins): add reply function

Add a `reply` function to baseplugin that can be used
to automatically send a return message in the same
way in which a command was received (PM back to a user
if the command as a PM, in a channel otherwise).

Resolves issue #1
https://github.com/collingreen/yaib/issues/1
feature (core): add `info` command to core

Add simple `info` command that prints a string about the Yaib
project. Can be configured in the core plugin settings.