[dialer] Install custom qDebug messages handler

Now it logs into ~/dialer.log, this way it can be retrieved even if
autostarted by Mission Control.

dialer/src/main.cpp

@@ -47,8 +47,35 @@
 #include <KAboutData>
 #include <KDBusService>
 
+#include <stdio.h>
+#include <stdlib.h>
+
+void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
+{
+    // TODO: print it on stdout too?
+    QFile file("/home/phablet/dialer.log");
+
+    bool opened = file.open(QIODevice::WriteOnly | QIODevice::Append);
+    Q_ASSERT(opened);
+
+    QTextStream out(&file);
+    out << QTime::currentTime().toString("hh:mm:ss.zzz ");
+    out << context.function << ":" << context.line << " ";
+
+    switch (type) {
+        case QtDebugMsg:	out << "DBG"; break;
+        case QtWarningMsg:  out << "WRN"; break;
+        case QtCriticalMsg: out << "CRT"; break;
+        case QtFatalMsg:    out << "FTL"; break;
+    }
+
+    out << " " << msg << '\n';
+    out.flush();
+}
+
 int main(int argc, char **argv)
 {
+    qInstallMessageHandler(myMessageOutput);
     QCommandLineParser parser;
     QApplication app(argc, argv);