generating only 2**(n-1) -1 subset instead of 2**n - 2. some tweaking for
fekete and opt lp
removal of some comments
added -r to record a graph and its solution to a png file. works also with -s
all; converted subset impl to old with in fekete lp; strange results in graphs
found plot to png bug; plt.figure() required for multiple plots
back to subset of size 2^(n-1) - 1 in feketes lp