Mixer not very accessible

The mixer is a bit of a mess with respect to accessibilty. Not only is the tab order random, but there is no good screen reader feedback on quite a few of the elements. In particular, the channel strips don't read the names of the channels, so you have no idea which track you are editing most of the time. It's possible this can be improved by tweaking what's there, but I know there are other proposals for larger scale mixer redesigns. Maybe it makes to jump in with those.