title: How to convert openerp 7 module to odoo 8
body: <p>Some useful module in openerp 7, such as "purchase_requisition_double_validation" but when installed there is error messages:</p>
  
  <pre><code>File "/opt/odoo/data/addons/purchase_requisition_analytic/analytic.py", line 22, in &lt;module&gt;
  from osv import fields, osv
  </code></pre>
  
  <p>ImportError: No module named osv</p>
  
  <p>So, how can I modify this module to make it Odoo 8 compatible?</p>
  
  <p>Thanks</p>