[IMP] - A canceled contract line can't be set to auto-renew

[REF] Contract: pep8

[IMP] Contract: update USAGE section of README

[IMP]call onchange_is_auto_renew when changing template

contract/models/contract.py

@@ -225,6 +225,7 @@ class AccountAnalyticAccount(models.Model):
             )
             new_lines += contract_line_model.new(vals)
         new_lines._onchange_date_start()
+        new_lines._onchange_is_auto_renew()
         return new_lines
 
     @api.multi