add: automatically recompute ground truth using SnPM13
fix: if bhPerms and StartPerm==2

If half the permutations are computed (i.e. `bhPerms` is true) and
StartPerm is 2 then the initial number of permutation can be 1 or 2
depending on sign of T0.
Update version to 13.01
fix: affecting testing only
fix: affecting tests only
Updates for SnPM13.01
fix: negative or zero start at 2
Merge SnPM13.01, now online