Included roads processing and area calculation
This merge request focuses on refining the built areas with the OBM_roads database, I included 4 new functions:
reproject_polygon: manages reprojecting polygons between different crs (generic to be used among other functions)
process_dataframe_with_tile: Process any dataframe with the tile specs (meant to be used with roads)
polygon_difference: Simple difference between 2 geometries
albers_area_calculation: does the albers transformation and calculates the area
I also included a Jupyter notebook for documentation of how a tile is being processed. I think it is important to have this explicit documentation with graphs.