src/Maze.js
function Cell(north, east, south, west) {
    this._north = north;
    this._east = east;
    this._south = south;
    this._west = west;
}
function Cell(north, east, south, west) {
    this._north = north;
    this._east = east;
    this._south = south;
    this._west = west;
}
function Cell ( north , east , south , west ) { this . _north = north ; this . _east = east ; this . _south = south ; this . _west = west ; }
A Cell is a wrapper object that makes it easier to
ask for passage information by name.

@constructor
@private
@param {integer} width
@param {integer} height
A Cell is a wrapper object that makes it easier to ask for passage information by name .