Done db queue creation, processing, started files

The queue table holds files to be processed. The indexing job will now
properly go through the queue providing each file to be processed.
Properly removing each batch of files from the queue as they're
processed.

The files table lists files that are missing copyright tags. The files
table no longer has a tagged column since it's redundant. We can assume
that all files listed in the table doesn't have copyright tags.

NOTE: Might have to index our custom tables for performance reasons.

Unfortunately, this commit is a bit too large as I forgot to commit.
There's two mixed up parts to the commit to help reduce confusing.
- Queue processing done.
- Processing the files table was just started.