Impacted versions:10

Steps to reproduce:
Following the code in https://www.odoo.com/documentation/10.0/api_integration.html both in a fresh install and against 'https://demo.odoo.com/start' trows a type error

Current behavior:
Now I get an error when executing:

```
ids = models.execute_kw(db, uid, password,  'res.partner', 'search',
    [[['is_company', '=', True], ['customer', '=', True]]],
    {'limit': 1})
[record] = models.execute_kw(db, uid, password,
    'res.partner', 'read', [ids])
# count the number of fields fetched by default
len(record)
```

In particular it seems to be a type error (cannot marshal class odoo.tools.float_utils.float_precision)

Expected behavior:
I would expect it to behave as in the documentation

may see different values for the field on a given record.
        :param company_dependent: whether the field is company-dependent (boolean)
        .. _field-incremental-definition:
        .. rubric:: Incremental definition
        A field is defined as class attribute on a model class. If the model
        is extended (see :class:`~openerp.models.Model`), one can also extend
        the field definition by redefining a field with the same name and same
        type on the subclass. In that case, the attributes of the field are
        taken from the parent class and overridden by the ones given in
        subclasses.
        For instance, the second class below only adds a tooltip on the field
        ``state``::
            class First(models.Model):
                _name = 'foo'
                state = fields.Selection([...], required=True)
            class Second(models.Model):
                _inherit = 'foo'
                state = fields.Selection(help="Blah blah blah")
    """
    __metaclass__ = MetaField
    type = None                         
    relational = False                  
    _slots = {
        'args': EMPTY_DICT,             
        '_attrs': EMPTY_DICT,           
        '_module': None,                
        '_setup_done': None,            
        'automatic': False,             
        'inherited': False,             
        'origin': None,