updated Array2d docs
added Map.prototype.loadTilesFromString() method
Updated Fov obj (fov.js)
 - updated to use Map object (map.js)
 - added map and canSeeThroughTileFunc params to Fov.prototype.checkLos(x0, y0, x1, y1, map, canSeeThroughTileFunc);
 - removed un-used Fov.prototype.mapTileBlocksLos(x, y, map)

Updated FovROT (fov-rot.js)
 - updated to use Map object (map.js)
 - docs cleanup

Updated game example