Allows columns to be turned off when creating a Table instance

[bradleyayers]

This would allow you to include a cut-down table for use in the non-detail page for a particular object, or to remove a checkbox column depending on some request-time variable.

[kwevej]

could be a Meta attribute called exclude (well that's not for instance, but would require to subclass first)
class Meta: exclude = ('checkbox1','checkbox2')
ModelForm does it the same way
possible relation: #11