Can now initialize board with FEN

Sources/Engine/Pieces/Rook.swift

@@ -0,0 +1,33 @@
+package class Rook: Piece {
+	package weak var board: Board?
+	package var kind: Kind = .Rook
+
+	package var unicodeRepresentation: String {
+		return color == .Black ? "♜" : "♖"
+	}
+	package var color: Color
+
+	package var position: Square.Position
+
+	package var pseudoLegalPositions: [Square.Position] {
+		return []
+	}
+
+	package var legalPositions: [Square.Position] {
+		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	}
+
+	package func move(dst: Square.Position) -> Bool {
+		return false
+	}
+
+	package func isLegal(pos: Square.Position) -> Bool {
+		return false
+	}
+
+	package init(color: Color, on position: Square.Position) {
+		self.color = color
+		self.position = position
+	}
+
+}