[bucket] Better greet probability
[bucket] Add a chance to refuse to accept items from unfriendly users

Use the "refuse to take item" factoid to teach bucket replies for that
[bucket] add some more debug info for <alias> recursion protection
[bucket] missing comma
[bucket] Allow bucket to be addressed in reverse

Sentences ending with the name of the bot will now also count as addressed.
This is experimental and I might remove it if it becomes too problematic.
[bucket] Remove recursion in inventory code

Not only using a recursion there was slow and it made the code unreadable,
the implementation was simply wrong: there was a chance bucket would return
banans even if there are available items still.

Also, fix a typo
[bucket] Fuck it.