Adapted the queens module to fix open issues

These two commits target the issues numberten/zhenya_bot#19 and numberten/zhenya_bot#20 as well as a bug which was noticed during development.

The bot should now friendly decline calculating boards with more than 25 rows/columns.

For boards smaller than 13 it should also print the board itself in addition to the list.

If there are no solutions, the bot answers that too.

If there is anything "haskelly", let me know too!