title: How to add simple many2one field in existing module on ODOO 8?
body: <p>I'm trying to create a simple many2one field in ODOO 8, in crm.lead view</p>
  
  <p>This is my code:</p>
  
  <p>campo_regione.py</p>
  
  <pre><code>from openerp import models, fields, osv
  class nome_regione(models.Model):
    _name = "nome_regione"
    _inherit = "crm.lead"
    name = fields.Char('Nome', size=20, required=True)
  class campo_regione(models.Model):
    _name = "campo_regione"
    _inherit = "crm.lead"
    _description = "Regione"
    campo_regione_id = fields.Many2one('nome_regione', 'Nome Regione')
  </code></pre>
  
  <p>campo_regione.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;openerp&gt;
     &lt;data&gt;
        &lt;record model = "ir.ui.view" id = "campo_regione"&gt;
           &lt;field name ="name"&gt;crm.regione.inherit&lt;/field&gt;
           &lt;field name = "model"&gt;crm.lead&lt;/field&gt;
           &lt;field name = "inherit_id" ref="crm.crm_case_form_view_leads"&gt;&lt;/field&gt;
           &lt;field name="arch" type="xml"&gt;
              &lt;xpath expr="//field[@name='country_id']" position="after"&gt;
                  &lt;field name="campo_regione_id"&gt;Regione&lt;/field&gt;
              &lt;/xpath&gt;
          &lt;/field&gt;
        &lt;/record&gt;
     &lt;/data&gt;
  &lt;/openerp&gt;
  </code></pre>
  
  <p>Now, after the module installs, odoo stops responding, even if I restart it, it goes on loop.</p>
  
  <p>I'm able to login only by renaming or deleting the new module.</p>
  
  <p>What am I wrong? thank you.</p>