Started category management
Merge branch 'master' of https://github.com/thelia/thelia
Added UrlRewritingTrait to manage URLs from model classes
Merge branch 'master' of https://github.com/thelia/thelia
Typo
Merge branch 'master' of https://github.com/thelia/thelia into coupon

# By franck
# Via franck
* 'master' of https://github.com/thelia/thelia:
  Typo
  Added UrlRewritingTrait to manage URLs from model classes
  Started category management
WIP : Coupon : unit tests on Operator