Change pieceview.js -> squareview.js
Change 'Queen' to 'Piece'
Change 'PieceView' to 'Squareview'; correct filename to 'squareview'
Add differentiated piece classes
Transition toward having piece.js manage piece movement
Reset source square
Reset target square
Amend accessors of piece properties
Refactor methods
Remove 'type' & 'color' attributes from Square models
Delete methods that have been transferred to piece.js
Enable pawn movement
Move functionality from square to piece & board
Delete pawn methods from square.js; move castling methods to piece.js
Call castlingVectors() on getVectors() dispatch
Duplicate rook & place it on target square during castling
Fully move rook during castling
Add differentiated piece classes; use Pawns instead of generic Pieces
Refactor pawn.js & piece.js
Override piece.js validate()