Adding 'nextWithError' method to FMResultSet to obtain error details

I am from a team in Cerner Corporation (http://www.cerner.com), and we would like to have a version of FMResult's 'next' method that populates an NSError out parameter, to distinguish true errors instead of returning no results.

We went though the conversation in the following link and thought that this was the right way to go.
https://github.com/ccgus/fmdb/issues/227