add order to how tags are shown

[gacafe]

• tags are shown in ui in an order that one can not change
• if one can change it how do you do so dynamically -- ie. place it in the middle, at the top or at the bottom?
• how does this work when yaml files update your data on load?

[silky]

A few thoughts cross my mind:

• It's probably acceptable to set this order "globally", rather than on the specific feature you are tagging.
• In general, it might be useful to send some metadata to b6 for usage by the UI. This already happens with the "centroid" and "docked" directives on the root collection

In detail, as discussed, it could look like:

• Setting a kind of "label-order" directive to something standard like: alphabetical, or similar.
• Hard-coding a list of labels in the given order; with any label not appearing in that list just being ordered subsequently alphabetically
• ???

The thing to work out would be how to provide this information.

Options:

• Add a new function, called set-label-ordering which would do this, and take effect in subsequent actions
• Provide it as a metadata config file to the b6 executable
• Provide it as a command-line arg to b6
• Add it as a new directive alongside "centroid" and "docked" (bit strange, as these typically refer to features)
• ???

I'd be tempted to go for the new function, or the metadata config file. Maybe the new function is a bit more idiomatic to how b6 works at present.