Add layout client unmanagement feature

features/layout/unmanage.feature

@@ -0,0 +1,10 @@
+Feature: layout client unmanagement
+
+  Background:
+    Given uhwm is running
+    And a first window is mapped
+    And a second window is mapped
+
+  Scenario: maps another window
+    When the second window requests to be unmapped
+    Then the first window must be mapped

features/steps/x_steps.rb

@@ -1,3 +1,7 @@
+Given /^a (\w+) window is mapped$/ do |ident|
+  x_window_map ident: ident
+end
+
 When /^I press the ([^ ]+) keys?$/ do |keys|
   x_key keys
 end
@@ -6,6 +10,10 @@ When /^a window requests to be mapped$/ do
   x_window_map
 end
 
+When /^the (\w+) window requests to be unmapped$/ do |ident|
+  x_window_unmap ident: ident
+end
+
 When /^a window requests to be mapped (\d+) times$/ do |times|
   x_window_map times: times.to_i
 end
@@ -19,6 +27,10 @@ Then /^the window must be mapped$/ do
   expect(x_window_map_state).to eq 'IsViewable'
 end
 
+Then /^the (\w+) window must be mapped$/ do |ident|
+  expect(x_window_map_state ident: ident).to eq 'IsViewable'
+end
+
 Then /^the window must be focused$/ do
   expect(x_focused_window_id).to eq x_window_id
 end