stability upgrade

app/models/list.rb

@@ -248,7 +248,7 @@ class List
   end
 
   def table_number
-    @table_number ||= table.number
+    @table_number ||= table.try(:number).to_i
   end
 
   def active?

app/models/order.rb

@@ -53,7 +53,7 @@ class Order
   end
 
   def table_number
-    list.table.number
+    list.table_number
   end
   alias table_nr table_number
 

app/models/supplier.rb

@@ -28,7 +28,7 @@ class Supplier
   has_many :tables, dependent: :destroy
   has_many :lists, dependent: :destroy
   #has_many :lists, through: :tables
-  has_many :orders
+  has_many :orders, dependent: :destroy
   has_many :sections, dependent: :destroy
 
   after_create :add_section_on_create