If I have two windows (A,B) in the secondary monitory (I have a two monitor setup), and I set A above B in workspace 1, then switch to workspace 2, and set B above A, I can now switch between the workspaces and the windows will change order, as depicted ascii-art-ly below.

Steps to Reproduce:
1. create window A and B, pull them both to the secondary screen
2. make sure you have two workspaces (create C and D and put one in each workspace)
3. switch to workspace 1, set A on top of B
4. go to workspace 2, set B on top of A
5. now switch back to 1

Expected behavior:
B remains on top of A

Actual behavior:
A becomes above B (i.e. it returns to the remembered state from workspace 1)

Additional info:

This state is remembered per workspace instead of globally - this is contradictory to the recently introduced notion that the non primary screens behave as though they have a single workspace. I would like to see that option toggleable, but at least for now it should be consistent, so if it's a single workspace it should have no per-workspace state.

Workspace 1:

----
|AA|
|AA|--
----B|
  |BB|
  ----

Workspace 2:

----
|AA|
|A----
--|BB|
  |BB|
  ----