Suggestion: User created sub-folders for Tags, Authors, Etc.

[Daemon]

The ability to organize our list of tags a bit more would be rather nice. I've only just started collecting and organizing ebooks from Project Gutenberg, and even though I'm stripping down the tags fairly heavily, I've already reached a point where the list of tags is getting a bit long.

A related upgrade would be the ability to select an entire folder with one click.

Suggested Usage:
Under "tags", for example, the user can create a folder and then manually place the tags into the folder for organization, such as creating a folder called "Folklore" and putting "Folklore (Ireland)" and "Folklore (Japan)" into it.
The user can then open the folder to select an individual tag, or select the folder itself to select all of the tags it contains.