* For each texture you view, it will reset back to mip 0 and slice 0
as it previously did, and it will also reset the channels back to
RGB only, which is new behaviour.
* Then each texture remembers those settings, so if you choose to view
slice 6 & alpha only of a texture any time you switch back to it
you'll see slice 6 & alpha only.
* It can be disabled in the options, but this is the new default
behaviour. Possibly in future the zoom level and visible range might
be rolled into this, but for now I think they might work better as
global state.
baldurk
80329f6e9b