I think this patch fixes the exception thrown when the sort
field includes None values. It may also fix the problem with
integers not sorting as integers.

Nagy, can you apply this (to roundup/cgi/templating.py)
and see if it fixes both this issue and issue2551122.

It also includes (commented out) code to address issue255112
by using the sort_repr function from the hyperdb base class
for the data type to sort by the base type of the data. I don't
think this is needed as using the _value from the HTMLProperty
object seems to make sorting correct.

Ralf it looks like the existing test code for test_templating is
not suitable for testing this. I think I need a real database
underneath it. Thoughts on how to test this.

-- rouilj