If app.useGUI is false, messages should use qWarning (or qDebug, qCritical or qFatal)
instead of QMessageBox.  This patch changes a few for testing.
Scribus 1.5 has about 250 calls to QMessageBox.
Can they be converted without duplicating the strings?

diff --git a/scribus/scribus.cpp b/scribus/scribus.cpp
--- a/scribus/scribus.cpp	2014-08-29 01:36:20.376668643 +0200
+++ b/scribus/scribus.cpp	2014-08-29 03:33:45.555606043 +0200
@@ -737,6 +737,12 @@
 bool ScribusMainWindow::warningVersion(QWidget *parent)
 {
 	bool retval = false;
+	if (!ScribusQApp::useGUI)
+	{
+		qWarning() << QObject::tr("Scribus Development Version");
+		qWarning() << QObject::tr("You are running a development version of Scribus 1.5.x. The document you are working with was created in Scribus 1.2.x.  Saving the current file under 1.5.x renders it unable to be edited in Scribus 1.2.x versions. To preserve the ability to edit in 1.2.x, save this file under a different name and further edit the newly named file and the original will be untouched. Are you sure you wish to proceed with this operation?");
+		return true;
+	}
 	int t = QMessageBox::warning(parent, QObject::tr("Scribus Development Version"), "<qt>" +
 								 QObject::tr("You are running a development version of Scribus 1.5.x. The document you are working with was created in Scribus 1.2.x.  Saving the current file under 1.5.x renders it unable to be edited in Scribus 1.2.x versions. To preserve the ability to edit in 1.2.x, save this file under a different name and further edit the newly named file and the original will be untouched. Are you sure you wish to proceed with this operation?") + "</qt>",
 								 QMessageBox::Ok | QMessageBox::Cancel, QMessageBox::Cancel);
@@ -3872,6 +3878,11 @@
 	QFileInfo fi(fileName);
 	if (!fi.exists())
 	{
+		if (!ScribusQApp::useGUI)
+		{
+			qWarning() << QString(tr("File does not exist on the specified path :\n%1")).arg(QDir::toNativeSeparators(fileName));
+			return false;
+		}
 		QMessageBox::warning(this, CommonStrings::trWarning, tr("File does not exist on the specified path :\n%1").arg(QDir::toNativeSeparators(fileName)), 
 		                           CommonStrings::tr_OK);
 		return false;
