[SQLObject] Possible bug in EnumCol/EnumValidator

Hi

Attached is a test case demonstrating the issue. Tested with version
1.5.0b1 and some previous versions.

The EnumValidator checks if the value given is in the list of valid
enumValues but this allows unicode values to match normal string values.

That allows unicode objects into the SQL generation code which forces
python to create unicode strings instead of normal strings. This means
already encoded values will be decoded again and probably with the wrong
encoding.

My guess is that the EnumValidator should return only str objects that
are properly encoded.

Regards
Gert Burger