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/colorbutton/colorbutton.cpp

@@ -1,7 +1,29 @@
+/***
+
+  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 "colorbutton.h"
 
 #include "dialog/color/colordialog.h"
 
+OLIVE_NAMESPACE_ENTER
+
 ColorButton::ColorButton(ColorManager* color_manager, QWidget *parent) :
   QPushButton(parent),
   color_manager_(color_manager),
@@ -59,3 +81,5 @@ void ColorButton::UpdateColor()
 
   setStyleSheet(QStringLiteral("ColorButton {background: %1;}").arg(managed.name()));
 }
+
+OLIVE_NAMESPACE_EXIT

app/widget/colorbutton/colorbutton.h

@@ -1,3 +1,23 @@
+/***
+
+  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 COLORBUTTON_H
 #define COLORBUTTON_H
 
@@ -6,6 +26,8 @@
 #include "render/color.h"
 #include "render/colormanager.h"
 
+OLIVE_NAMESPACE_ENTER
+
 class ColorButton : public QPushButton
 {
   Q_OBJECT
@@ -36,4 +58,6 @@ private:
 
 };
 
+OLIVE_NAMESPACE_EXIT
+
 #endif // COLORBUTTON_H