Update and rename us.poly to north-america.poly

polygon wasn't us only; also modified polygon as it included Greenland which is actually not part of north-america
Update updateRegions.sh
Update script.sh

Create north-america.pbf and canada.pbf for mega cities
Add Canadian mega cities
Add Edmonton, Canada as well
Update updateRegions.sh
Update updateRegions.sh
Merge pull request #65 from hvdwolf/master

change us.poly to north-america.poly; update updateRegions.sh; add necessary pbfs; add canadian polies