switch to a algorithm with two matrices (but optimized to have 1 matrix
while tracking indices and just a single row if only scoring) that can be
proven to always provide the optimal result (fzfs' v2 algorithm does not
and can even produce wore results than its v1 algorithm). The algorithm
is very similar to skim but still uses fzfs bonus system and is orders
of magnitude faster (and falls back to fzfs greedy v1 algorithm which is
actually surprisingly close to the optimal algorithm).
