Add missing macros to sdi.h
FIX: Pass locale settings to get<>() method for string conversions
FIX: m_sqlstate is already defined in base class
FIX: If resultset is empty, set cursor state to POSITIONED

This fixes an issue with empty resultsets.
If the first fetch returns no row, the cursor state must
be set to POSITIONED and EOF.
FIX: Check SQL_NO_DATA before !SQL_SUCCEEDED()