[BUG] cutsize and ratio_cut no longer sparse scalars

Issue was summing the adjacency matrix (which was sparse) to calculate
cutsize. sum(sum(SPARSE_MATRIX)) is still sparse, even if it's a scalar.
Added placement vector output in metrics object
[BUG][MAJOR] Fixed incorrect min_ind and min cutsize/ratiocut calculation

was not taking the minimum of the actual cutsize and ratio cut vectors,
was just taking the min of the cutsize or ratio_cut scalar reported for
the last cut attempted