Added Oracle schema and queries files for use with dhcp_sqlippool

Alan, Arran,

These files contain the Oracle schema and queries for dhcp_sqlippool which I have successfuly used with an Oracle DB. I started with the queries for MySQL and changed them until I got them working with Oracle. I am no SQL expert, so the queries may not be optimal in terms of speed. However, they are tested and working with Oracle 11g and FreeRADIUS v3.0.x.

I had some problems when the queries were split over multiple lines and this is why each one here is on one long line.

Regards

Ben