currentDirectoryIds etc are global computed properties
move disks into content
filter by polys work
filter by one of the current poly
Poly#name != Poly#nameOnDisk (because of Directory#name vs relative_path)
can subscribe a Directory, redirect back
autodetection of root dirs

cannot link to new directories directly because they have no poly yet.
autodetection of subdirs

Emu uses #parent for internal whatever, so we have to name the
association parentDirectory.
list stays intact when viewing a torrent

because we were leaving the 'running' page.

Want filtering / query param routing nao!
fight the timing