Include necessary headers for gcc-4.4, bug fix for 550264
--- a/easy_plot/src/gnuplot_connection.cpp
+++ b/easy_plot/src/gnuplot_connection.cpp
@@ -2,6 +2,7 @@
 #include <QXmlStreamReader>
 #include <QXmlStreamWriter>
 #include <QHash>
+#include <cstdio>
 
 GnuplotConnection::GnuplotConnection(QObject *parent):QProcess(parent)
 {