Fixing the middle-wide layout focus sequence

[kelvinst]

Fixes #1189

Basically, it goes in the wrong direction because the left column is marked as the "secondary", and when going clockwise it goes in the sequence main -> secondary -> terciary... So if we just switch secondary to right and terciary to left, it should go in the right direction.

[ianyh]

The problem with changing it now is that it would change the behavior out from under people already using it. I hate to say it, but maybe just add an option to that enum for a mirrored middle or something like that.

[kelvinst]

I see. Yeah, another option looks like a good option, should I change this PR to do that then?

[ianyh]

I see. Yeah, another option looks like a good option, should I change this PR to do that then?

Yeah, if you make that change I can take a look.

[rwjack]

In that case, could we just have another Layout named 3Column Middle (Fill Right first) - or something similar, not to break the layout for users that got used to the current workings of it.