Make order of categories configurable

[cellio]

Currently categories are shown in the order created, but a site might want to put other things before Meta or insert other things after the site has been up for a while. It would be better if the order could be configured.

One way to do this would be to add a "priority" option to a category's configuration. Treat it like Z-index; allow gaps, so a site could set Meta to 99 and just not worry about it as it adjusts the relative priorities of its blog, sandbox, and contests (or whatever). If two categories specify the same priority, either complain (if that's easy to catch at edit time) or just fall back to some defined behavior like "oldest first". This will be an infrequent operation; it doesn't need a beautiful UI with drag-and-drop and suchlike.

[manassehkatz]

As I noted elsewhere - no UI needed to handle it. Just have the SQL query reading the category list do an order by priority, id

[ArtOfCode-]

Completed by 7622e81