fix uninitialized pointer variables in some classes

apps/openmw/mwgui/inventorywindow.cpp

@@ -39,6 +39,8 @@ namespace MWGui
         , mPreviewDirty(true)
         , mPreviewResize(true)
         , mDragAndDrop(dragAndDrop)
+        , mSortModel(NULL)
+        , mTradeModel(NULL)
         , mSelectedItem(-1)
         , mGuiMode(GM_Inventory)
     {

apps/openmw/mwgui/mainmenu.cpp

@@ -29,6 +29,7 @@ namespace MWGui
         , mButtonBox(0), mWidth (w), mHeight (h)
         , mSaveGameDialog(NULL)
         , mBackground(NULL)
+        , mVideoBackground(NULL)
         , mVideo(NULL)
     {
         getWidget(mVersionText, "VersionText");

apps/openmw/mwgui/spellcreationdialog.cpp

@@ -447,8 +447,12 @@ namespace MWGui
 
     EffectEditorBase::EffectEditorBase(Type type)
         : mAddEffectDialog()
+        , mAvailableEffectsList(NULL)
+        , mUsedEffectsView(NULL)
         , mSelectAttributeDialog(NULL)
         , mSelectSkillDialog(NULL)
+        , mSelectedEffect(0)
+        , mSelectedKnownEffectId(0)
         , mType(type)
     {
         mAddEffectDialog.eventEffectAdded += MyGUI::newDelegate(this, &EffectEditorBase::onEffectAdded);

apps/openmw/mwgui/windowmanagerimp.cpp

@@ -123,6 +123,7 @@ namespace MWGui
       , mScreenFader(NULL)
       , mDebugWindow(NULL)
       , mTranslationDataStorage (translationDataStorage)
+      , mSoftwareCursor(NULL)
       , mCharGen(NULL)
       , mInputBlocker(NULL)
       , mCrosshairEnabled(Settings::Manager::getBool ("crosshair", "HUD"))