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/render/color.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 "color.h"
 
+OLIVE_NAMESPACE_ENTER
+
 Color Color::fromHsv(const float &h, const float &s, const float &v)
 {
   float C = s * v;
@@ -182,7 +204,9 @@ QColor Color::toQColor() const
   return c;
 }
 
-QDebug operator<<(QDebug debug, const Color &r)
+OLIVE_NAMESPACE_EXIT
+
+QDebug operator<<(QDebug debug, const OLIVE_NAMESPACE::Color &r)
 {
   debug.nospace() << "[R: " << r.red() << ", G: " << r.green() << ", B: " << r.blue() << ", A: " << r.alpha() << "]";
   return debug.space();