various: encapsulate all code in the olive namespace to avoid name collisions

Large-scale code cleanup. Also adds a license to the top of all files that were
missing it.

app/widget/playbackcontrols/dragbutton.cpp

@@ -1,5 +1,27 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  This program 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.
+
+  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
 #include "dragbutton.h"
 
+OLIVE_NAMESPACE_ENTER
+
 DragButton::DragButton(QWidget *parent) :
   QPushButton(parent)
 {
@@ -10,3 +32,5 @@ void DragButton::mousePressEvent(QMouseEvent *event) {
 
   emit MousePressed();
 }
+
+OLIVE_NAMESPACE_EXIT

app/widget/playbackcontrols/dragbutton.h

@@ -1,8 +1,32 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  This program 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.
+
+  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
 #ifndef DRAGBUTTON_H
 #define DRAGBUTTON_H
 
 #include <QPushButton>
 
+#include "common/define.h"
+
+OLIVE_NAMESPACE_ENTER
+
 class DragButton : public QPushButton
 {
   Q_OBJECT
@@ -17,4 +41,6 @@ protected:
 
 };
 
+OLIVE_NAMESPACE_EXIT
+
 #endif // DRAGBUTTON_H

app/widget/playbackcontrols/playbackcontrols.cpp

@@ -28,6 +28,8 @@
 #include "config/config.h"
 #include "ui/icons/icons.h"
 
+OLIVE_NAMESPACE_ENTER
+
 PlaybackControls::PlaybackControls(QWidget *parent) :
   QWidget(parent),
   time_base_(0)
@@ -220,3 +222,5 @@ void PlaybackControls::TimecodeChanged()
   // Update end time
   SetEndTime(end_time_);
 }
+
+OLIVE_NAMESPACE_EXIT

app/widget/playbackcontrols/playbackcontrols.h

@@ -30,6 +30,8 @@
 #include "dragbutton.h"
 #include "widget/slider/timeslider.h"
 
+OLIVE_NAMESPACE_ENTER
+
 /**
  * @brief A playback controls widget providing buttons for navigating media
  *
@@ -132,4 +134,6 @@ private slots:
 
 };
 
+OLIVE_NAMESPACE_EXIT
+
 #endif // PLAYBACKCONTROLS_H