Bug fixes:
#47 -nprocs removed in keyplayer kp-info command line
#48 empty result with kp-finder
#49 -seed argument removed in pyntacle generator
#50 --plot-format option removed from 1.2 onward
#51 seed argument removed in group degree API
#52 bad handling of missing output file names
#53 bad handling of empty set due to graph intersection