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

openerp/fields.py
searching on that field is done by the database itself. The disadvantage
        is that it requires database updates when the field must be recomputed.
        The inverse method, as its name says, does the inverse of the compute
        method: the invoked records have a value for the field, and you must
        apply the necessary changes on the field dependencies such that the
        computation gives the expected value. Note that a computed field without
        an inverse method is readonly by default.
        The search method is invoked when processing domains before doing an
        actual search on the model. It must return a domain equivalent to the
        condition: ``field operator value``.
        .. _field-related:
        .. rubric:: Related fields
        The value of a related field is given by following a sequence of
        relational fields and reading a field on the reached model. The complete
        sequence of fields to traverse is specified by the attribute
        :param related: sequence of field names
        Some field attributes are automatically copied from the source field if
        they are not redefined: ``string``, ``help``, ``readonly``, ``required`` (only
        if all fields in the sequence are required), ``groups``, ``digits``, ``size``,
        ``translate``, ``sanitize``, ``selection``, ``comodel_name``, ``domain``,
        ``context``. All semantic-free attributes are copied from the source
        field.
        By default, the values of related fields are not stored to the database.
        Add the attribute ``store=True`` to make it stored, just like computed
        fields. Related fields are automatically recomputed when their
        dependencies are modified.
        .. _field-company-dependent:
        .. rubric:: Company-dependent fields
        Formerly known as 'property' fields, the value of those fields depends
        on the company. In other words, users that belong to different companies