templates/datagrid.jinja: jinja2 does not define enumerate function.
… Replaced enumerate iteration index with loop.index0 variable
Various smaller fixes and cleanups.
Fix these tests and the tested functionality.
Corrected typo that prevented Calendar widget of being rendered.
Make twf.Label validate to twc.EmptyField
Just the same as twf.Space. Otherwise, the validates results will include a None key which makes e.g. TurboGears2 choke if the dict is passed as method kwargs.