20111216
========

Continued on :srcref:`docs/tickets/52`. 
The CalendarStore not only needed a `idProperty` but also an `idIndex` config option.
I didn't understand 100% why, but now it works perfectly.

The `color` of a :class:`lino_xl.lib.cal.Calendar` no longer 
is a virtual field but a simple `models.IntegerField`. There's currently 
not even a ComboBox (because Lino doesn't yet know how to implement Comboboxes for Integers), 
users must know that this field is meant to contain a value between 1 and 32.
At least

One important thing is missing before we can say that CalendarPanel 
is integrated: creating and updating events doesn't work because my handlers 
currently don't forward it to Lino.

There is also an almost philosphical question: where should the label "Calendar" 
(and it's translations) be defined? Currently it is in 
:class:`lino.reports.Calendar`. The whole pot-pourri of actors and actions 
(Report, Frame, Detail, Action) might get an internal revision soon: 

- is it necessary to instantiate Actors? 
  Should the instantiation of an actor represent a request?
- Split "Report" into "List" and "Detail": both of them get their own store. 
  Note that one Detail would contain the equivalent of all .dtl files.
  Replace .dtl files (one per tab) by a single configuration file.
  The possibility of local configuration should remain, but convert them to Python code.
- Actions should be rather like fields: instantiated within the subclass definition.