Easy win: check for missing bound parameters

[g105b]

When I miss passing a bound parameter, I see the error message You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near :theNameOfTheMissedParam

This is because that string isn't being replaced, and isn't valid SQL.

This should be easy to detect and provide a more meaningful error message with.

This will improve #29 too.