
* Threading:

Uploads run in parallel with main fs operation.
Otherwise, main fs operation is single-threaded.
Could multi-thread the rest but would have to lock the
cache properly first.

Right now, only one upload at a time.
Could have more by kicking off multiple
uploader procs.

* Implement subcategories.

* Implement renames of categories.

* Implement renames of albums.

* Implement album settings file.

* Implement image settings file.