reduce kconfig.sync() calls

--improves startup times in some cases because
it does not write to disk that often.

app/layout/abstractlayout.cpp

@@ -364,8 +364,6 @@ void AbstractLayout::saveConfig()
     m_layoutGroup.writeEntry("customTextColor", m_customTextColor);
     m_layoutGroup.writeEntry("lastUsedActivity", m_lastUsedActivity);
     m_layoutGroup.writeEntry("preferredForShortcutsTouched", m_preferredForShortcutsTouched);
-
-    m_layoutGroup.sync();
 }
 
 }

app/layout/centrallayout.cpp

@@ -50,9 +50,6 @@ CentralLayout::CentralLayout(QObject *parent, QString layoutFile, QString assign
 
 CentralLayout::~CentralLayout()
 {
-    if (!m_layoutFile.isEmpty()) {
-        m_layoutGroup.sync();
-    }
 }
 
 void CentralLayout::unloadContainments()
@@ -256,8 +253,6 @@ void CentralLayout::saveConfig()
     m_layoutGroup.writeEntry("disableBordersForMaximizedWindows", m_disableBordersForMaximizedWindows);
     m_layoutGroup.writeEntry("sharedLayout", m_sharedLayoutName);
     m_layoutGroup.writeEntry("activities", m_activities);
-
-    m_layoutGroup.sync();
 }
 
 //! OVERRIDES

app/layout/storage.cpp

@@ -158,7 +158,6 @@ void Storage::syncToLayoutFile(bool removeLayoutId)
 
     KConfigGroup oldContainments = KConfigGroup(filePtr, "Containments");
     oldContainments.deleteGroup();
-    oldContainments.sync();
 
     qDebug() << " LAYOUT :: " << m_layout->name() << " is syncing its original file.";
 

app/layouts/manager.cpp

@@ -307,10 +307,6 @@ void Manager::cleanupOnStartup(QString path)
     for (const auto &cId : removeContaimentsList) {
         containmentGroups.group(cId).deleteGroup();
     }
-
-
-    actionGroups.sync();
-    containmentGroups.sync();
 }
 
 
@@ -332,8 +328,6 @@ void Manager::clearUnloadedContainmentsFromLinkedFile(QStringList containmentsId
         KConfigGroup containment = containments.group(conId);
         containment.deleteGroup();
     }
-
-    containments.sync();
 }
 
 QString Manager::newLayout(QString layoutName, QString preset)

app/plasma/extended/theme.cpp

@@ -624,8 +624,6 @@ void Theme::loadConfig()
 void Theme::saveConfig()
 {
     m_themeGroup.writeEntry("outlineWidth", m_outlineWidth);
-
-    m_themeGroup.sync();
 }
 
 }

app/settings/universalsettings.cpp

@@ -507,8 +507,6 @@ void UniversalSettings::saveConfig()
     m_universalGroup.writeEntry("showInfoWindow", m_showInfoWindow);
     m_universalGroup.writeEntry("memoryUsage", (int)m_memoryUsage);
     m_universalGroup.writeEntry("mouseSensitivity", (int)m_sensitivity);
-
-    m_universalGroup.sync();
 }
 
 void UniversalSettings::cleanupSettings()

app/view/indicator/indicator.cpp

@@ -439,8 +439,6 @@ void Indicator::saveConfig()
     config.writeEntry("customType", m_customType);
     config.writeEntry("enabled", m_enabled);
     config.writeEntry("type", m_type);
-
-    config.sync();
 }
 
 }

app/view/settings/primaryconfigview.cpp

@@ -778,7 +778,6 @@ void PrimaryConfigView::saveConfig()
     auto config = m_latteView->containment()->config();
     int complexity = m_inAdvancedMode ? 1 : 0;
     config.writeEntry("settingsComplexity", complexity);
-    config.sync();
 }
 //!END configuration
 

app/view/view.cpp

@@ -1548,7 +1548,6 @@ void View::saveConfig()
     config.writeEntry("byPassWM", byPassWM());
     config.writeEntry("isPreferredForShortcuts", isPreferredForShortcuts());
     config.writeEntry("viewType", (int)m_type);
-    config.sync();
 }
 
 void View::restoreConfig()