old h5shuffle does not work with new indexed files
Using the old h5shuffle command on a file that includes graphs as samples with indices does not work, because the samples dataset has an attribute that is a bool and pytables can't read that.
Solution: Use 1,0 instead of True, False for the 'indexed' attribute and adjust the reading of this attribute everywhere in OrcaSong and OrcaNet.
But h5shuffle should not be used anymore anyways because h5shuffle2 is faster. So I'll leave it for now...