hz-cell doesn't handle updates to data

[Matt Borland]

Unless you're using a template, hz-cell doesn't handle updates to data. This is because there is nothing to tell Angular that anything of value has changed. It's evaluated once and then done.

To solve this, instead of using $scope.column, just pass the column in explicitly as a parameter. Angular will then know that it's valuable.

You can see this in the implementation of Images (https://review.openstack.org/#/c/309561/); if you update "Protected" it is updated in the drawer but not in the table column.

[Matt Borland (palecrow)]

Note, if the idea is that we use the table's track-by, it will update all row elements...so perhaps this is not a huge concern. Either way, it seems a better model to pass in the parameter than to assume it's on scope.