Merge branch 'master' into tax

Conflicts:
	core/lib/Thelia/Config/Resources/action.xml
	core/lib/Thelia/Controller/Admin/AddressController.php
	core/lib/Thelia/Controller/Admin/CustomerController.php
	core/lib/Thelia/Controller/Admin/ModuleController.php

core/lib/Thelia/Model/CartItem.php

@@ -60,7 +60,14 @@ class CartItem extends BaseCartItem
             }
         }
 
-        $this->setQuantity($value);
+        $this->addQuantity($value);
+
+        return $this;
+    }
+
+    public function addQuantity($quantity)
+    {
+        $this->setQuantity($this->getQuantity() + $quantity);
 
         return $this;
     }

core/lib/Thelia/Model/ConfigQuery.php

@@ -56,7 +56,7 @@ class ConfigQuery extends BaseConfigQuery {
 
     public static function getPageNotFoundView()
     {
-        return self::read("page_not_found_view", '404');
+        return self::read("page_not_found_view", '404.html');
     }
 
     public static function getPassedUrlView()

core/lib/Thelia/Model/Country.php

@@ -13,6 +13,9 @@ class Country extends BaseCountry
 
     public function toggleDefault()
     {
+        if($this->getId() === null) {
+            throw new \RuntimeException("impossible to just uncheck default country, choose a new one");
+        }
         CountryQuery::create()
             ->filterByByDefault(1)
             ->update(array('ByDefault' => 0));
@@ -47,6 +50,10 @@ class Country extends BaseCountry
 
     public function preDelete(ConnectionInterface $con = null)
     {
+        if($this->getByDefault()) {
+            return false;
+        }
+
         $this->dispatchEvent(TheliaEvents::BEFORE_DELETECOUNTRY, new CountryEvent($this));
 
         return true;