Super calendar improvement

[Sergio Corato]

Changing the field type from datetime to date in v. 6.0, the super_calendar can be used with both date and datetime fields.

Rows modified in super_calendar.py:

'date_start_field_id': fields.many2one('ir.model.fields', 'Start date field',
            domain="['&',('ttype', '=', 'date'),('model_id', '=', name)]",
            required=True),

'date_start':fields.date('Start date', required=True),

[Sergio Corato (icsergio)]

Moreover, cron_data.xml could be modified to be active and without limit of call, adding these lines:

     <field name="numbercall">-1</field>
     <field name="active">True</field>