implemented a footage viewer

Essentially a minor derivation of a viewer type that can automatically view
footage from the project (i.e. not in a sequence).

app/panel/viewer/viewer.cpp

@@ -21,7 +21,7 @@
 #include "viewer.h"
 
 ViewerPanel::ViewerPanel(QWidget *parent) :
-  PanelWidget(parent)
+  ViewerPanelBase(parent)
 {
   // FIXME: This won't work if there's ever more than one of this panel
   setObjectName("ViewerPanel");
@@ -37,61 +37,6 @@ ViewerPanel::ViewerPanel(QWidget *parent) :
   Retranslate();
 }
 
-void ViewerPanel::ZoomIn()
-{
-  viewer_->SetScale(viewer_->scale() * 2);
-}
-
-void ViewerPanel::ZoomOut()
-{
-  viewer_->SetScale(viewer_->scale() * 0.5);
-}
-
-void ViewerPanel::GoToStart()
-{
-  viewer_->GoToStart();
-}
-
-void ViewerPanel::PrevFrame()
-{
-  viewer_->PrevFrame();
-}
-
-void ViewerPanel::PlayPause()
-{
-  viewer_->TogglePlayPause();
-}
-
-void ViewerPanel::NextFrame()
-{
-  viewer_->NextFrame();
-}
-
-void ViewerPanel::GoToEnd()
-{
-  viewer_->GoToEnd();
-}
-
-void ViewerPanel::ShuttleLeft()
-{
-  viewer_->ShuttleLeft();
-}
-
-void ViewerPanel::ShuttleStop()
-{
-  viewer_->ShuttleStop();
-}
-
-void ViewerPanel::ShuttleRight()
-{
-  viewer_->ShuttleRight();
-}
-
-void ViewerPanel::SetTimebase(const rational &timebase)
-{
-  viewer_->SetTimebase(timebase);
-}
-
 void ViewerPanel::ConnectViewerNode(ViewerOutput *node)
 {
   viewer_->ConnectViewerNode(node);