Floating layer, select left/right fails about wmii HOT 2 OPEN

This is an enhancement, not a defect. The floating layer has no columns, so 
up/down,
left/right retain their meaning. up/down switches between clients in the given 
area,
left/right switches between areas. Making left/right work requires different
semantics, and I haven't decided on any yet.

Perhaps you could cycle between (1) client positions on the screen and (2) 
z-index:

[client0]
  [client1]
  [client2]

When client2 is focused, and left is pressed, it would focus client0 because 
it's the
nearest left client.  If up is pressed, it would focus client1 because it's the
nearest up client.

[client0/1]

When clients overlap each other, up/down can cycle the z-index.

What do you think?