Added
- The `enable playground` Configuration directive.
Changed
- The behavior of the `label` option of `list collect` no longer
prints text before `1.`, `2.`, etc. Now the `label` supplies the
whole label for the item, and it can include the number by way of
the index variable.
Fixed
- The `list collect` feature raised an exception when the field
definition included Mako substitution.
- Non-required upload fields were creating zero-byte files on some
servers.