Remove deletes for images from scroll list GUI Elements

Resources are deleted by ~PageSet and do not need to be deleted
by the the scrollable list elements. This fixes a crash when
reloading the theme.

Also remove some deletes for items that should not be deleted in
button and input GUI elements.

Change-Id: Ie1c1b85c81c10f648d085746a5fdba6220468a5f

gui/button.cpp

@@ -130,7 +130,6 @@ GUIButton::~GUIButton()
 	if (mButtonImg)	 	delete mButtonImg;
 	if (mButtonLabel)   delete mButtonLabel;
 	if (mAction)		delete mAction;
-	if (mButtonIcon)	delete mButtonIcon;
 }
 
 int GUIButton::Render(void)

gui/fileselector.cpp

@@ -141,8 +141,6 @@ GUIFileSelector::GUIFileSelector(xml_node<>* node) : GUIScrollList(node)
 
 GUIFileSelector::~GUIFileSelector()
 {
-	delete mFileIcon;
-	delete mFolderIcon;
 }
 
 int GUIFileSelector::Update(void)

gui/input.cpp

@@ -214,8 +214,6 @@ GUIInput::GUIInput(xml_node<>* node)
 GUIInput::~GUIInput()
 {
 	if (mInputText)	 	delete mInputText;
-	if (mBackground)	delete mBackground;
-	if (mCursor)		delete mCursor;
 	if (mAction)		delete mAction;
 }
 

gui/listbox.cpp

@@ -103,8 +103,6 @@ GUIListBox::GUIListBox(xml_node<>* node) : GUIScrollList(node)
 
 GUIListBox::~GUIListBox()
 {
-	delete mIconSelected;
-	delete mIconUnselected;
 }
 
 int GUIListBox::Update(void)

gui/partitionlist.cpp

@@ -96,8 +96,6 @@ GUIPartitionList::GUIPartitionList(xml_node<>* node) : GUIScrollList(node)
 
 GUIPartitionList::~GUIPartitionList()
 {
-	delete mIconSelected;
-	delete mIconUnselected;
 }
 
 int GUIPartitionList::Update(void)

gui/scrolllist.cpp

@@ -259,9 +259,6 @@ GUIScrollList::GUIScrollList(xml_node<>* node) : GUIObject(node)
 
 GUIScrollList::~GUIScrollList()
 {
-	delete mHeaderIcon;
-	delete mBackground;
-	delete mFont;
 }
 
 void GUIScrollList::SetMaxIconSize(int w, int h)