Correct crash when closing editor Panel with hidden history

Remeber last option about hidden/shown panel

rtgui/editorpanel.cc

@@ -466,6 +466,7 @@ void EditorPanel::hideHistoryActivated () {
     removeIfThere (hpanedl, leftbox, false);
     if (hidehp->get_active()) 
         hpanedl->pack1 (*leftbox, false, true);
+    options.showHistory = hidehp->get_active();
 }
 
 bool EditorPanel::handleShortcutKey (GdkEventKey* event) {

rtgui/previewwindow.cc

@@ -20,17 +20,18 @@
 #include <guiutils.h>
 #include <imagearea.h>
 
-PreviewWindow::PreviewWindow () : previewHandler(NULL), mainCropWin(NULL), isMoving(false) {
+PreviewWindow::PreviewWindow () : previewHandler(NULL), mainCropWin(NULL), isMoving(false),cCropMoving(NULL),cNormal(NULL) {
 
     rconn = signal_size_allocate().connect( sigc::mem_fun(*this, &PreviewWindow::on_resized) );
 }
 
 PreviewWindow::~PreviewWindow () {
 
-    delete cCropMoving;
-#ifndef WIN32
-    delete cNormal;
-#endif
+	if( cCropMoving )
+		delete cCropMoving;
+	if( cNormal )
+		delete cNormal;
+
 }
 
 void PreviewWindow::on_realize () {