Exception when FORCE_LOWERCASE_TAGS is set

[GoogleCodeExporter]

A simple flow of multiple tag selection:

From user input, run utility function parse_tag_input and receive a list.

Set this list to a tag field when FORCE_LOWERCASE_TAGS is set.

method: def __set__(self, instance, value): is called

lines 70,71:

if settings.FORCE_LOWERCASE_TAGS and value is not None:
            value = value.lower()

this fails with exception since value is a list and not a string. There should 
be test for a list and lowercase the list one by one if needed.

Original issue reported on code.google.com by [email protected] on 2 Feb 2011 at 7:32