[spam][spam][spam] walking robot algorithm parts

[Undescribed Horrific Abuse, One Victim & Survivor of Many]

note:
- when trying to lift feet, this can only be done if the resulting
convex support polygon still includes the center of mass. otherwise
the foot is holding unique weight.
- if the foot will not be holding unique weight, it makes sense to
immediately lift it, so as to place it somewhere needed sooner
- when bounds are reached we know what areas need new coverage with
the support polygon

it was supposed to work with an arbitrary number of legs which i
find/found cool.

undetermined areas could use a heuristic or look farther along
possible path planning to decide where to go