Changed to use SQLLEN where appropriate (possible omissions, needs testing)
(cherry picked from commit bfa1e2271fa6409ff6dfe3753bc47656b4cff37d)
Use SQLINTEGER and SQLDOUBLE instead of long and double in ConvertColumnValue/GetCColumnType
(cherry picked from commit c88022f32c7070f0d644cfdc0785217d0f31c7c0)