adding a sample script splot osm files
adding requirements file
Ajout d'un fichier exemple de quadrillage
Added libgdal-dev to the readme
Cleanup the apt-get install in the readme.
added libspatialindex-dev to the apt deps in the readme
added rtree to the requirements
fixed path to the extract script
Merge pull request #1 from mlhamel/master

Updating the documentation and the dependencies