Clean up headers && fix compilation with (the upcoming) qt 4.8.2

Conflicts:

	src/adblock/adblockwidget.h
	src/application.h
	src/history/historymanager.h
	src/tabpreviewpopup.cpp

Backported from master branch

1 files changed, 2 insertions, 2 deletions

diff --git a/src/sessionmanager.h b/src/sessionmanager.h
index b4748fde..810d9b5c 100644
--- a/src/sessionmanager.h
+++ b/src/sessionmanager.h
@@ -34,10 +34,10 @@
 #include "rekonq_defines.h"
 
 // Qt Includes
-#include <QtCore/QObject>
+#include <QObject>
+#include <QString>
 
 // Forward Declarations
-class QString;
 class TabHistory;
 class MainWindow;