Add the function 'Pawn.move-legal?'; fix
parameter dependencies of some functions; fix typos.
Adapt the spec 'PAWN.move-legal?' to the use of
the coughsyrup class 'Pawn'.
Remove static currying by the function
'Piece.navigable-path-to-tgt?'.
Add fns 'move' and 'position' to the 'King' class.
Add the fn 'gs.opponent-at?'; refactor the
fns 'plausible-assault-on-tgt?', 'gs.tgt-assailable-from-src?', and
'gs.tgt-assailed?'; add the constant 'namespaces2'; fix bug in the
fn 'plausible-assault-on-tgt?'.
Adapt specs for the fn
'Pawn.plausible-assault-on-tgt?' to a new parameter interface.
Delete container objects KING, QUEEN, ROOK,
BISHOP, KNIGHT, PAWN, PIECE, and SUBJECT and most references to them.
Amend comments.
Use the word 'rights' rather than 'permissions' for
greater succinctness.
Factor out additional references to former container classes.