Default action for CheckboxColumn is to show/hide alert widget. We no longer needs to setHandler to manage visibility of Alert.
OPAL-1928: Delete category, clearing control group error
OPAL-1928: Reorder categories is working and getting categories locales based from table locales.
Merge pull request #272 from emorency/feature/OPAL-1928-categories-edit-ui

OPAL-1928: Categories Editor UI. MoveUp/Down and locales from table locales