Added possibility for creating vouchers from other module.

shop/shopservice.cpp

@@ -375,3 +375,14 @@ void ShopService::updateVoucher(VoucherPtr entity)
 
     tr.commit();
 }
+
+void ShopService::eraseVoucher(VoucherPtr entity)
+{
+    Transaction tr;
+    odb::database *db = Context::instance().db();
+
+    db->execute(QString("DELETE FROM VoucherItem WHERE voucher = %1").arg(entity->id()).toStdString());
+    db->erase(entity);
+
+    tr.commit();
+}