which makes MySQL field types to Python functions which perform the
conversion. All numeric types except DECIMAL are mapped into either
PyInt or PyLong, and the floating point types are mapped into PyFloat by
default. Types which are not represented in the dictionary are returned
as strings.
Modified MySQLdb to adjust type_conv so that the various date/time types
are returned as DateTime objects.
Bug: If you were to delete or assign type_conv, bad things would happen.
I haven't actually tried this, but it wouldn't be good. May add an extra
reference count to prevent this, haven't really decided.
