* Use global state instead of per-layout - so now window is minimized on
all workspaces (EWMH requires that windows with _NET_WM_STATE_HIDDEN
set should be minimized on any workspace but previously they were not)
* Use `windows` instead of `modify`. That should fix bugs related to
actions that should be done by `windows` and not done by
`modify` (fixes#46)
* Mark module X.H.RestoreMinimized as deprecated
Commits d638dc8b and a5e87e38 introduced a per-AvoidStruts-instance
strut cache that
a) didn't get initialized at startup,
b) didn't get reinitialized after layout reset and
c) didn't get updates if it wasn't the active layout, for example when
layoutHook = avoidStruts tall ||| avoidStruts (mirror tall)
a) + b) could be fixed by using the docksStartupHook introduced in
28e9f8bc, although this wasn't documented and having to call
docksStartupHook after setLayout is far from obvious.
By moving the strut cache from AvoidStruts instances to a global state,
b) and c) are fixed. One still has to invoke the docksStartupHook for
a), and this will be addressed in the next commit.
Calling these functions during message handling results in the loss of layout state.
This fixes a number of bugs related to the combination of X.L.Minimize with a decoration.
