title: Odoo [OpenERP] Custom module KeyError issue
body: <p>I am trying to add my own custom made module in odoo for test purpose. However, I am continuously getting the below error. Below is how my code looks like. Please help in this regard</p>
  
  <blockquote>
    <p><strong>_init</strong>.py</p>
  </blockquote>
  
  <pre><code>import select_custom
  </code></pre>
  
  <blockquote>
    <p>select_custom.py</p>
  </blockquote>
  
  <pre><code>from openerp.osv import osv, fields
  
  class select_custom(osv.Model):
      _inherit = 'select.custom'
  
      _columns = {
          'productChoose' : fields.many2one('hr.employee', 'Product Choose')
          }
  </code></pre>
  
  <blockquote>
    <p>select_custom_view.xml</p>
  </blockquote>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;openerp&gt;
      &lt;data&gt;
          &lt;record id="view_custom_tick_box_form" model="ir.ui.view"&gt;
              &lt;field name="name"&gt;res.custom.tick.form.inherit&lt;/field&gt;
              &lt;field name="model"&gt;select.custom&lt;/field&gt;
              &lt;field name="inherit_id" ref="purchase.purchase_order_form"/&gt;
              &lt;field name="arch" type="xml"&gt;
                  &lt;field name="date_order" position="after"&gt;
                      &lt;field name="productChoose"/&gt;
                  &lt;/field&gt;
              &lt;/field&gt;
          &lt;/record&gt;
      &lt;/data&gt;
  &lt;/openerp&gt;
  </code></pre>
  
  <p>I am getting the below error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\http.py", line 537, in _handle_exception
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\http.py", line 574, in dispatch
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\http.py", line 310, in _call_function
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\service\model.py", line 113, in wrapper
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\http.py", line 307, in checked_call
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\http.py", line 803, in __call__
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\http.py", line 403, in response_wrap
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\openerp\addons\web\controllers\main.py", line 948, in call_button
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\openerp\addons\web\controllers\main.py", line 936, in _call_kw
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\api.py", line 241, in wrapper
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\openerp\addons\base\module\module.py", line 450, in button_immediate_install
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\api.py", line 241, in wrapper
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\openerp\addons\base\module\module.py", line 498, in _button_immediate_function
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\modules\registry.py", line 370, in new
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\modules\loading.py", line 355, in load_modules
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\modules\loading.py", line 255, in load_marked_modules
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\modules\loading.py", line 152, in load_module_graph
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\modules\registry.py", line 163, in load
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\models.py", line 595, in _build_model
    File "C:\Program Files (x86)\Odoo 8.0-20150621\server\.\openerp\modules\registry.py", line 102, in __getitem__
  KeyError: 'select.custom'
  </code></pre>