20110916
========

notes.EventType has now a new BabelTextField `body`.

Moved `LanguageField` and `LANGUAGE_CHOICES` from 
:mod:`lino.fields` to
:mod:`lino.utils.babel`.

:class:`lino.utils.babel.BabelTextField` 
now creates `RichTextField` fields, not `models.TextField`

There was an undiscovered bug
in :class:`lino.utils.babel.BabelTextField`: 
it would have created babel children 
also when used on abstract models.