Fix handling for user -1 (not logged in)

Fixes #2228.  This turned out to be a much more pervasive problem in how
not being logged in was handled.  I've changed this to closer to how it
should be, that not being logged is is just the same as being user -1,
and its permissions apply, aside from the isLoggedIn function, which was
not actually used correctly either.
Increase default DB queue size

See #2237
Throttle transcode starts during ingesting

This will make ingests a lot slower, but fixes #2237
Truncate asset.name to 32 chars in fileName

Fixes #2241
#2185 - institution thumbnails scale instead of crop
Fix transcode collection error handling: hack owner = -1

Should be fixed better, possibly only by recording errors when a
matching asset is found.
Audio isn't transcodable for now
Fix simple volume search not to match all with "undefined"