Bad default radio view rendering

Bug: Default rendering of list and radio fields outputs values, not text 
captions.

diff of Widget.py:

443c443,460
<
---
 >
 >     def render_item_view(self, field, value):
 >         items = field.get_value('items')
 >         for item in items:
 >             try:
 >                 item_text, item_value = item
 >             except ValueError:
 >                 item_text = item
 >                 item_value = item
 >             if value==item_value:
 >                 return item_text
 >         raise KeyError, "Wrong item value"
 >
 >     def render_view(self, field, value):
 >         if value is None:
 >             return ''
 >         return self.render_item_view(field, value)
 >
558,562d574
<     def render_view(self, field, value):
<         if value is None:
<             return ''
<         return value
<
643,647d654
<     def render_view(self, field, value):
<         if value is None:
<             return ''
<         return value
<