getList::prepVal to use a given datatype

[john3571]

prepVal should accept a second parameter which forces the function to output using a given SQL datatype.

Acceptable values could include boolean, integer, varchar, float or any other SQL datatype or abbreviation. If a problem occurs during casting to a datatype, an error should be thrown.

[stanistan]

We need to move this out of prepVal, it's a much more generic method -- prepVal should use it.

Suggestions on where this should go?