Add --raw flag

Updated dbus API. Now it sends a signal with every capture, it may
be captureFailed or a captureTaken which contains the raw image
bytes in png format. You have to add an id to the screenshot calls
so it will be returned as a way to know the origin of the signal.

src/utils/dbusutils.cpp

@@ -0,0 +1,55 @@
+// Copyright 2017 Alejandro Sirgo Rica
+//
+// This file is part of Flameshot.
+//
+//     Flameshot is free software: you can redistribute it and/or modify
+//     it under the terms of the GNU General Public License as published by
+//     the Free Software Foundation, either version 3 of the License, or
+//     (at your option) any later version.
+//
+//     Flameshot is distributed in the hope that it will be useful,
+//     but WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//     GNU General Public License for more details.
+//
+//     You should have received a copy of the GNU General Public License
+//     along with Flameshot.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "dbusutils.h"
+#include "src/utils/systemnotification.h"
+#include <QApplication>
+#include <QTextStream>
+#include <QFile>
+
+DBusUtils::DBusUtils(QObject *parent) : QObject(parent) {
+    m_id = qHash(qApp->arguments().join(" "));
+}
+
+DBusUtils::DBusUtils(uint id, QObject *parent) :
+    QObject(parent), m_id(id)
+{
+}
+
+void DBusUtils::checkDBusConnection(const QDBusConnection &c) {
+    if (!c.isConnected()) {
+        SystemNotification().sendMessage(tr("Unable to connect via DBus"));
+        qApp->exit();
+    }
+}
+
+void DBusUtils::captureTaken(uint id, QByteArray rawImage) {
+    if (m_id == id) {
+        QFile file;
+        file.open(stdout, QIODevice::WriteOnly);
+        file.write(rawImage);
+        file.close();
+        qApp->exit();
+    }
+}
+
+void DBusUtils::captureFailed(uint id) {
+    if (m_id == id) {
+        QTextStream(stdout) << "screenshot failed";
+        qApp->exit();
+    }
+}