stockpile: working with groups

[aixtools]

The basic interface is click on "stockpile" button and "add to group", either new or existing.

• I miss an option to 'reset' or "remove' a stockpile from a group, e.g., put in a group by accident.

• A stockpile can be moved to a new group by either adding it to a new group, OR selecting an existing group. THIS seems confusing (if you have used tags) because it looks the same as tags (you can have multiple tags) - so imho, a radio button would be better here (for existing groups) to make it clearer that groups is 'one' or 'none'.