Update pdo_odbc to use SQLLEN where appropriate

Many ODBC APIs were changed to use SQLLEN instead of SQLINTEGER. This
has the benefit of allowing 64-bit parameters on 64-bit platforms, but
causes problems if your application is not updated to use these 64-bit
types. If you pass a pointer to the wrong size variable, you will get
unpredictible results.as the driver will read or write to random memory.

For more information, see
http://msdn.microsoft.com/en-us/library/windows/desktop/ms716287%28v=vs.85%29.aspx

This was changed in Windows Server 2003 on Windows and in unixODBC
2.2.14, which was released in November 2008. It's about time it was
fixed in pdo_odbc.