Mix work dump 1

This is most of the work for mixes. they work, it just needs to be
cleaned up plus do stuff like delete/hide. Mostly just using this as a
backup.
Rest of mix work

Mixes now fully added... only problem is that they slow down startup and
background threads are confusing
make mixes load faster

dump loading into background so that app doesn't take 10 seconds to load
with mixes
thumbs

apparently this changed? not sure what this is...
Fix jumpy scroll issue

added hack so listviewer no longer jumps around when scrolling