[sr-dev] (k) radius accounting

Starting with 3.1.x, (k) radius accounting is done via a new module (acc_radius). However, the acc module is still refering to radius files via the RAD_ACC flag. In order to keep the code clean, the RAD_ACC and the associated code should be removed from the acc module. If someone will compile kamailio with the RAD_ACC flag enabled an it will try to use radius accounting via the acc_radius module, we will have some conflicts: acc with radius enabled and acc_radius. Regards, Ovidiu Sas