added the reference to the radio domain range in the accumulator

passing an extra information to the gridded accumulator: the sequential number of the first projection of an angular subchunk. This is needed togeter with the global indexes of every projection ( which were already passed ). The latters indexes the total sequence of darks flats and radios plus invalid frames. But it is important to have also the partial index ( radios only ) in order to use properly arrays like currents, which run on radios only