options: enable separate screen focus by default

When the user closes the active window, with separate screen focus disabled, a
window on the other screen might get activated, which also switches the active
screen to the other one. As this is quite unintuitive, and in my testing having
separate screen focus enabled didn't have any other unintuitive side effects,
this commit enables separate screen focus by default

autotests/integration/lockscreen.cpp

@@ -211,6 +211,7 @@ void LockScreenTest::init()
 
     workspace()->setActiveOutput(QPoint(640, 512));
     input()->pointer()->warp(QPoint(640, 512));
+    options->setSeparateScreenFocus(false);
 }
 
 void LockScreenTest::cleanup()

src/kcms/options/kwinoptions_settings.kcfg

@@ -132,7 +132,7 @@
     </entry>
 
     <entry key="SeparateScreenFocus" type="Bool">
-        <default>false</default>
+        <default>true</default>
     </entry>
 
     <entry key="FocusStealingPreventionLevel" type="Int">

src/kwin.kcfg

@@ -98,7 +98,7 @@
             <default>false</default>
         </entry>
         <entry name="SeparateScreenFocus" type="Bool">
-            <default>false</default>
+            <default>true</default>
         </entry>
         <entry name="RollOverDesktops" type="Bool">
             <default>false</default>

src/options.cpp

@@ -40,7 +40,7 @@ Options::Options(QObject *parent)
     , m_delayFocusInterval(0)
     , m_shadeHover(false)
     , m_shadeHoverInterval(0)
-    , m_separateScreenFocus(false)
+    , m_separateScreenFocus(true)
     , m_placement(PlacementNone)
     , m_activationDesktopPolicy(Options::defaultActivationDesktopPolicy())
     , m_borderSnapZone(0)