Update CHANGELOG.

static/plugin_event/CHANGELOG

@@ -8,10 +8,12 @@ HEAD
   - The form for event uses the card layout.
   - In the event table, data model information are displayed using
     the Table widget.
-  - for list and metric, the conditions can be written using the web2py
+  - For list and metric, the conditions can be written using the web2py
     syntax for database query. Therefore, it can deal with foreign tables
     of the history table as well as with the history.data field.
   - Rename the class MySelector as EvtSelector.
+  - Add the method EvtSelector._active_period to compute properly
+    EvtSelector._is_start, _is_end as well as is_over.
   - Factorize the application around the plugin_event.
 
 0.6.2 (Nov 2016)