Clean headers in ProjectExplorer.

Change-Id: If61a8a91d2a39c5c97974a5bfcef91892b68d3f1
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/qt4projectmanager/qmakekitconfigwidget.cpp

@@ -35,6 +35,8 @@
 #include <coreplugin/icore.h>
 #include <projectexplorer/projectexplorerconstants.h>
 
+#include <utils/fileutils.h>
+
 #include <QLineEdit>
 
 namespace Qt4ProjectManager {