20120712
========

- Removed MySentInvitations and MyPendingSentInvitations because the 
  owner of a team event will not manage invitations one by one, she 
  will rather just go to "My notified events".
  
- Added new email template `Event/Team.eml.html` used to 
  notify team members of changes in an event. 
  Depending on the event's state, the mail is formulated as 
  invitation, reminder or confirmation.

- New method 
  :meth:`after_state_change <lino.core.modeltools.Model.after_state_change>`.
  Modified signature of 
  :meth:`before_state_change <lino.core.modeltools.Model.before_state_change>`:
  added a `kw` argument where subclasses may update the action response.
  
  Example usage is :meth:`lino_xl.lib.cal.Event.after_state_change`.
  
  TODO: store the action response into the 
  :class:`ActionRequest <lino.core.actions.ActionRequest>`   
  and remove the `kw` argument.
  
- New method 
  :meth:`after_state_change <lino.core.modeltools.Model.after_sendmail>`.
  An event changes automatically from "suggested" to "notified" when it 
  has been sent by email.
  
- Added `ar` (the 
  :class:`ActionRequest <lino.core.actions.ActionRequest>`) 
  to the CheetahTemplate context during 
  :meth:`lino.modlib.outbox.Mailable.get_mailable_intro`.
  
- The guests of a team event (i.e. whose Calendar.invite_team_members is set)  
  Are now filled independently of the access_class.
  A private team event will be seen by those who are invited, 
  but not by other users.