Impacted versions:
9.0, 10.0, 11.0 (Maybe 8.0)
I don't know if it is really an expected behaviour for odoo but I like to expose it

Steps to reproduce:

1. Open an ir.cron record and change it to:
 - interval: minutes
 - next execution date: now + 1 minute

2. Open the odoo server log

Note: I'm using workers=3 but I don't know if there is possible to reproduce it without workers.

Current behavior:

You will see for each cron execution the following output
```txt
...
2018-06-01 16:18:33,432 20686 INFO 333561-11-0-42aff9-all odoo.modules.registry: Invalidating all model caches after database signaling.
...
2018-06-01 16:17:21,527 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: loading 1 modules...
2018-06-01 16:17:21,535 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: 1 modules loaded in 0.01s, 0 queries
2018-06-01 16:17:21,594 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: loading 206 modules...
2018-06-01 16:17:21,718 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: 206 modules loaded in 0.12s, 0 queries
2018-06-01 16:17:21,989 20687 INFO 333561-11-0-42aff9-all odoo.modules.loading: Modules loaded.
```

Expected behavior:
 - Review if the method that run from the cron really requires a invalidate cache and delete all registries.
 - Disable "minutes" for cron interval because all cache are deleted then is not valid use them.

Video/Screenshot link (optional):

 - [![IMAGE ALT TEXT HERE](https://img.youtube.com/vi/Be4FIeQjgjk/0.jpg)](https://youtu.be/Be4FIeQjgjk)
""" Return a function mapping a field to an integer. The value of a
            field is guaranteed to be strictly greater than the value of the
            field's dependencies.
        """
        
        dependents = {
            field: set(dep for dep, _ in model._field_triggers[field] if dep != field)
            for model in self.itervalues()
            for field in model._fields.itervalues()
        }
        
        mapping = {
            field: num
            for num, field in enumerate(reversed(topological_sort(dependents)))
        }
        return mapping.get
    def clear_manual_fields(self):
        """ Invalidate the cache for manual fields. """
        self._fields_by_model = None
    def get_manual_fields(self, cr, model_name):
        """ Return the manual fields (as a dict) for the given model. """
        if self._fields_by_model is None:
            
            self._fields_by_model = dic = defaultdict(dict)
            cr.execute('SELECT * FROM ir_model_fields WHERE state=%s', ('manual',))
            for field in cr.dictfetchall():
                dic[field['model']][field['name']] = field
        return self._fields_by_model[model_name]
    def do_parent_store(self, cr):