Remove #glean-map.
Remove redundant #type-from.
Add constants for individual chessmen;
refactor #king-position; prepare for additional restructuring.
Amend #king-position by
adding assertions and including #to-2d so to return a pos rather than an index.
Add specs for #king-position.
Amend #king-safe? so that
the position of the king is automatically located.
Add specs for #king-safe?.