This change concerns with the addition of 'select_variable' property to 'Standard Property' object which is required because while trying to display properties form for any ERP5 object which contains at-least one property of selection or multiple selection type, rendering usually fails with an error "'select_varaible' is not defined".

This is because of this section in properties.dtml file regarding rendering of properties of type selection or multiple selection.

<dtml-elif "type=='selection'">
  <dtml-if "hasProperty(select_variable)">

<dtml-elif "type=='multiple selection'">
  <dtml-if "hasProperty(select_variable)">

This behaviour can be checked by trying to access properties form for any portal_type object.

Please review: @romain