On buildFromTileLayer, flatten the tileLayer data to a 1D array for easier iteration; also, instance each grid item as custom MapTile class to allow for custom 'blocked' property
Allow the add / remove of 'sprites' to the navMesh, temp overrides that block movement across the tileLayer; these manipulate the aforementioned blocked property.
buildFromTileLayer, flatten the tileLayer data to a 1D array for easier iteration; also, instance each grid item as customMapTileclass to allow for custom 'blocked' propertyblockedproperty.Closes #10