add form_evolution to variables

wcs/formdata.py

@@ -252,6 +252,8 @@ class FormData(StorableObject):
         if d['form_status'] == d['form_previous_status']:
             d['form_status_changed'] = True
 
+        d['form_evolution'] = self.formdef.get_detailed_evolution(self)
+
         d.update(self.formdef.get_substitution_variables())
 
         if self.formdef.workflow and self.status:

wcs/workflows.py

@@ -925,8 +925,11 @@ def template_on_formdata(formdata, template, process=None):
     else:
         dict['comment'] = ''
     dict.update(formdata.get_as_dict())
+
+    # compatibility vars
     dict['before'] = dict.get('form_previous_status')
     dict['after'] = dict.get('form_status')
+    dict['evolution'] = dict.get('form_evolution')
 
     if process:
         for key in dict: