Ensure that item fields have the proper type.

The item fields were not setting their type based on the reported
field's type attribute, so values were not being encoded properly.

Fixes issue #121

sleekxmpp/plugins/xep_0004/stanza/form.py

@@ -96,11 +96,11 @@ class Form(ElementBase):
         self.xml.append(itemXML)
         reported_vars = self['reported'].keys()
         for var in reported_vars:
-            fieldXML = ET.Element('{%s}field' % FormField.namespace)
-            itemXML.append(fieldXML)
-            field = FormField(xml=fieldXML)
+            field = FormField()
+            field._type = self['reported'][var]['type']
             field['var'] = var
             field['value'] = values.get(var, None)
+            itemXML.append(field.xml)
 
     def add_reported(self, var, ftype=None, label='', desc='', **kwargs):
         kwtype = kwargs.get('type', None)