WIP Coupon

Refactor : creating dedicated reusable module for Constraints
Adding ConstraintManager
Secured :
- Effects : RemoveXPercent + RemoveXAmount
- Validators : all  except ModelParam (need CustomerModelParam, AreaModelParam, CountryModelParam ?)
- Conditions : AvailableForTotalAmount

core/lib/Thelia/Coupon/CouponAdapterInterface.php

@@ -131,4 +131,12 @@ interface CouponAdapterInterface
      */
     public function getTranslator();
 
+    /**
+     * Return the main currency
+     * THe one used to set prices in BackOffice
+     *
+     * @return string
+     */
+    public function getMainCurrency();
+
 }