Jkarni/feature/import feedback - DO NOT MERGE

@talbs this is the branch with import feedback stuff.

It has some of my really janky css, which I'd be glad to remove. There's also some debug stuff that I'll take out before any merge.

The important part is in `assets.js`, in the `getStatus` function. The `status` variable can be any number from 0 to 3 (inclusive). You can see the meaning of each in the comment to `import_status`. I would guess that the best way to update the interface is to call some update function in the body of `getStatus` every time `status` changes.