Add preliminaries for signal viewer, update version number, switch dbc handler to singleton pattern, changes to DBC attributes

signalviewerwindow.h

@@ -0,0 +1,22 @@
+#ifndef SIGNALVIEWERWINDOW_H
+#define SIGNALVIEWERWINDOW_H
+
+#include <QDialog>
+
+namespace Ui {
+class SignalViewerWindow;
+}
+
+class SignalViewerWindow : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit SignalViewerWindow(QWidget *parent = 0);
+    ~SignalViewerWindow();
+
+private:
+    Ui::SignalViewerWindow *ui;
+};
+
+#endif // SIGNALVIEWERWINDOW_H